first commit

.venv/Lib/site-packages/pandas/tests/plotting/common.py

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+"""
+Module consolidating common testing functions for checking plotting.
+
+Currently all plotting tests are marked as slow via
+``pytestmark = pytest.mark.slow`` at the module level.
+"""
+
+from __future__ import annotations
+
+import os
+from typing import (
+    TYPE_CHECKING,
+    Sequence,
+)
+import warnings
+
+import numpy as np
+
+from pandas.util._decorators import cache_readonly
+import pandas.util._test_decorators as td
+
+from pandas.core.dtypes.api import is_list_like
+
+import pandas as pd
+from pandas import (
+    DataFrame,
+    Series,
+    to_datetime,
+)
+import pandas._testing as tm
+
+if TYPE_CHECKING:
+    from matplotlib.axes import Axes
+
+
+@td.skip_if_no_mpl
+class TestPlotBase:
+    """
+    This is a common base class used for various plotting tests
+    """
+
+    def setup_method(self, method):
+
+        import matplotlib as mpl
+
+        from pandas.plotting._matplotlib import compat
+
+        self.compat = compat
+
+        mpl.rcdefaults()
+
+        self.start_date_to_int64 = 812419200000000000
+        self.end_date_to_int64 = 819331200000000000
+
+        self.mpl_ge_2_2_3 = compat.mpl_ge_2_2_3()
+        self.mpl_ge_3_0_0 = compat.mpl_ge_3_0_0()
+        self.mpl_ge_3_1_0 = compat.mpl_ge_3_1_0()
+        self.mpl_ge_3_2_0 = compat.mpl_ge_3_2_0()
+
+        self.bp_n_objects = 7
+        self.polycollection_factor = 2
+        self.default_figsize = (6.4, 4.8)
+        self.default_tick_position = "left"
+
+        n = 100
+        with tm.RNGContext(42):
+            gender = np.random.choice(["Male", "Female"], size=n)
+            classroom = np.random.choice(["A", "B", "C"], size=n)
+
+            self.hist_df = DataFrame(
+                {
+                    "gender": gender,
+                    "classroom": classroom,
+                    "height": np.random.normal(66, 4, size=n),
+                    "weight": np.random.normal(161, 32, size=n),
+                    "category": np.random.randint(4, size=n),
+                    "datetime": to_datetime(
+                        np.random.randint(
+                            self.start_date_to_int64,
+                            self.end_date_to_int64,
+                            size=n,
+                            dtype=np.int64,
+                        )
+                    ),
+                }
+            )
+
+        self.tdf = tm.makeTimeDataFrame()
+        self.hexbin_df = DataFrame(
+            {
+                "A": np.random.uniform(size=20),
+                "B": np.random.uniform(size=20),
+                "C": np.arange(20) + np.random.uniform(size=20),
+            }
+        )
+
+    def teardown_method(self, method):
+        tm.close()
+
+    @cache_readonly
+    def plt(self):
+        import matplotlib.pyplot as plt
+
+        return plt
+
+    @cache_readonly
+    def colorconverter(self):
+        import matplotlib.colors as colors
+
+        return colors.colorConverter
+
+    def _check_legend_labels(self, axes, labels=None, visible=True):
+        """
+        Check each axes has expected legend labels
+
+        Parameters
+        ----------
+        axes : matplotlib Axes object, or its list-like
+        labels : list-like
+            expected legend labels
+        visible : bool
+            expected legend visibility. labels are checked only when visible is
+            True
+        """
+        if visible and (labels is None):
+            raise ValueError("labels must be specified when visible is True")
+        axes = self._flatten_visible(axes)
+        for ax in axes:
+            if visible:
+                assert ax.get_legend() is not None
+                self._check_text_labels(ax.get_legend().get_texts(), labels)
+            else:
+                assert ax.get_legend() is None
+
+    def _check_legend_marker(self, ax, expected_markers=None, visible=True):
+        """
+        Check ax has expected legend markers
+
+        Parameters
+        ----------
+        ax : matplotlib Axes object
+        expected_markers : list-like
+            expected legend markers
+        visible : bool
+            expected legend visibility. labels are checked only when visible is
+            True
+        """
+        if visible and (expected_markers is None):
+            raise ValueError("Markers must be specified when visible is True")
+        if visible:
+            handles, _ = ax.get_legend_handles_labels()
+            markers = [handle.get_marker() for handle in handles]
+            assert markers == expected_markers
+        else:
+            assert ax.get_legend() is None
+
+    def _check_data(self, xp, rs):
+        """
+        Check each axes has identical lines
+
+        Parameters
+        ----------
+        xp : matplotlib Axes object
+        rs : matplotlib Axes object
+        """
+        xp_lines = xp.get_lines()
+        rs_lines = rs.get_lines()
+
+        def check_line(xpl, rsl):
+            xpdata = xpl.get_xydata()
+            rsdata = rsl.get_xydata()
+            tm.assert_almost_equal(xpdata, rsdata)
+
+        assert len(xp_lines) == len(rs_lines)
+        [check_line(xpl, rsl) for xpl, rsl in zip(xp_lines, rs_lines)]
+        tm.close()
+
+    def _check_visible(self, collections, visible=True):
+        """
+        Check each artist is visible or not
+
+        Parameters
+        ----------
+        collections : matplotlib Artist or its list-like
+            target Artist or its list or collection
+        visible : bool
+            expected visibility
+        """
+        from matplotlib.collections import Collection
+
+        if not isinstance(collections, Collection) and not is_list_like(collections):
+            collections = [collections]
+
+        for patch in collections:
+            assert patch.get_visible() == visible
+
+    def _check_patches_all_filled(
+        self, axes: Axes | Sequence[Axes], filled: bool = True
+    ) -> None:
+        """
+        Check for each artist whether it is filled or not
+
+        Parameters
+        ----------
+        axes : matplotlib Axes object, or its list-like
+        filled : bool
+            expected filling
+        """
+
+        axes = self._flatten_visible(axes)
+        for ax in axes:
+            for patch in ax.patches:
+                assert patch.fill == filled
+
+    def _get_colors_mapped(self, series, colors):
+        unique = series.unique()
+        # unique and colors length can be differed
+        # depending on slice value
+        mapped = dict(zip(unique, colors))
+        return [mapped[v] for v in series.values]
+
+    def _check_colors(
+        self, collections, linecolors=None, facecolors=None, mapping=None
+    ):
+        """
+        Check each artist has expected line colors and face colors
+
+        Parameters
+        ----------
+        collections : list-like
+            list or collection of target artist
+        linecolors : list-like which has the same length as collections
+            list of expected line colors
+        facecolors : list-like which has the same length as collections
+            list of expected face colors
+        mapping : Series
+            Series used for color grouping key
+            used for andrew_curves, parallel_coordinates, radviz test
+        """
+        from matplotlib.collections import (
+            Collection,
+            LineCollection,
+            PolyCollection,
+        )
+        from matplotlib.lines import Line2D
+
+        conv = self.colorconverter
+        if linecolors is not None:
+
+            if mapping is not None:
+                linecolors = self._get_colors_mapped(mapping, linecolors)
+                linecolors = linecolors[: len(collections)]
+
+            assert len(collections) == len(linecolors)
+            for patch, color in zip(collections, linecolors):
+                if isinstance(patch, Line2D):
+                    result = patch.get_color()
+                    # Line2D may contains string color expression
+                    result = conv.to_rgba(result)
+                elif isinstance(patch, (PolyCollection, LineCollection)):
+                    result = tuple(patch.get_edgecolor()[0])
+                else:
+                    result = patch.get_edgecolor()
+
+                expected = conv.to_rgba(color)
+                assert result == expected
+
+        if facecolors is not None:
+
+            if mapping is not None:
+                facecolors = self._get_colors_mapped(mapping, facecolors)
+                facecolors = facecolors[: len(collections)]
+
+            assert len(collections) == len(facecolors)
+            for patch, color in zip(collections, facecolors):
+                if isinstance(patch, Collection):
+                    # returned as list of np.array
+                    result = patch.get_facecolor()[0]
+                else:
+                    result = patch.get_facecolor()
+
+                if isinstance(result, np.ndarray):
+                    result = tuple(result)
+
+                expected = conv.to_rgba(color)
+                assert result == expected
+
+    def _check_text_labels(self, texts, expected):
+        """
+        Check each text has expected labels
+
+        Parameters
+        ----------
+        texts : matplotlib Text object, or its list-like
+            target text, or its list
+        expected : str or list-like which has the same length as texts
+            expected text label, or its list
+        """
+        if not is_list_like(texts):
+            assert texts.get_text() == expected
+        else:
+            labels = [t.get_text() for t in texts]
+            assert len(labels) == len(expected)
+            for label, e in zip(labels, expected):
+                assert label == e
+
+    def _check_ticks_props(
+        self, axes, xlabelsize=None, xrot=None, ylabelsize=None, yrot=None
+    ):
+        """
+        Check each axes has expected tick properties
+
+        Parameters
+        ----------
+        axes : matplotlib Axes object, or its list-like
+        xlabelsize : number
+            expected xticks font size
+        xrot : number
+            expected xticks rotation
+        ylabelsize : number
+            expected yticks font size
+        yrot : number
+            expected yticks rotation
+        """
+        from matplotlib.ticker import NullFormatter
+
+        axes = self._flatten_visible(axes)
+        for ax in axes:
+            if xlabelsize is not None or xrot is not None:
+                if isinstance(ax.xaxis.get_minor_formatter(), NullFormatter):
+                    # If minor ticks has NullFormatter, rot / fontsize are not
+                    # retained
+                    labels = ax.get_xticklabels()
+                else:
+                    labels = ax.get_xticklabels() + ax.get_xticklabels(minor=True)
+
+                for label in labels:
+                    if xlabelsize is not None:
+                        tm.assert_almost_equal(label.get_fontsize(), xlabelsize)
+                    if xrot is not None:
+                        tm.assert_almost_equal(label.get_rotation(), xrot)
+
+            if ylabelsize is not None or yrot is not None:
+                if isinstance(ax.yaxis.get_minor_formatter(), NullFormatter):
+                    labels = ax.get_yticklabels()
+                else:
+                    labels = ax.get_yticklabels() + ax.get_yticklabels(minor=True)
+
+                for label in labels:
+                    if ylabelsize is not None:
+                        tm.assert_almost_equal(label.get_fontsize(), ylabelsize)
+                    if yrot is not None:
+                        tm.assert_almost_equal(label.get_rotation(), yrot)
+
+    def _check_ax_scales(self, axes, xaxis="linear", yaxis="linear"):
+        """
+        Check each axes has expected scales
+
+        Parameters
+        ----------
+        axes : matplotlib Axes object, or its list-like
+        xaxis : {'linear', 'log'}
+            expected xaxis scale
+        yaxis : {'linear', 'log'}
+            expected yaxis scale
+        """
+        axes = self._flatten_visible(axes)
+        for ax in axes:
+            assert ax.xaxis.get_scale() == xaxis
+            assert ax.yaxis.get_scale() == yaxis
+
+    def _check_axes_shape(self, axes, axes_num=None, layout=None, figsize=None):
+        """
+        Check expected number of axes is drawn in expected layout
+
+        Parameters
+        ----------
+        axes : matplotlib Axes object, or its list-like
+        axes_num : number
+            expected number of axes. Unnecessary axes should be set to
+            invisible.
+        layout : tuple
+            expected layout, (expected number of rows , columns)
+        figsize : tuple
+            expected figsize. default is matplotlib default
+        """
+        from pandas.plotting._matplotlib.tools import flatten_axes
+
+        if figsize is None:
+            figsize = self.default_figsize
+        visible_axes = self._flatten_visible(axes)
+
+        if axes_num is not None:
+            assert len(visible_axes) == axes_num
+            for ax in visible_axes:
+                # check something drawn on visible axes
+                assert len(ax.get_children()) > 0
+
+        if layout is not None:
+            result = self._get_axes_layout(flatten_axes(axes))
+            assert result == layout
+
+        tm.assert_numpy_array_equal(
+            visible_axes[0].figure.get_size_inches(),
+            np.array(figsize, dtype=np.float64),
+        )
+
+    def _get_axes_layout(self, axes):
+        x_set = set()
+        y_set = set()
+        for ax in axes:
+            # check axes coordinates to estimate layout
+            points = ax.get_position().get_points()
+            x_set.add(points[0][0])
+            y_set.add(points[0][1])
+        return (len(y_set), len(x_set))
+
+    def _flatten_visible(self, axes):
+        """
+        Flatten axes, and filter only visible
+
+        Parameters
+        ----------
+        axes : matplotlib Axes object, or its list-like
+
+        """
+        from pandas.plotting._matplotlib.tools import flatten_axes
+
+        axes = flatten_axes(axes)
+        axes = [ax for ax in axes if ax.get_visible()]
+        return axes
+
+    def _check_has_errorbars(self, axes, xerr=0, yerr=0):
+        """
+        Check axes has expected number of errorbars
+
+        Parameters
+        ----------
+        axes : matplotlib Axes object, or its list-like
+        xerr : number
+            expected number of x errorbar
+        yerr : number
+            expected number of y errorbar
+        """
+        axes = self._flatten_visible(axes)
+        for ax in axes:
+            containers = ax.containers
+            xerr_count = 0
+            yerr_count = 0
+            for c in containers:
+                has_xerr = getattr(c, "has_xerr", False)
+                has_yerr = getattr(c, "has_yerr", False)
+                if has_xerr:
+                    xerr_count += 1
+                if has_yerr:
+                    yerr_count += 1
+            assert xerr == xerr_count
+            assert yerr == yerr_count
+
+    def _check_box_return_type(
+        self, returned, return_type, expected_keys=None, check_ax_title=True
+    ):
+        """
+        Check box returned type is correct
+
+        Parameters
+        ----------
+        returned : object to be tested, returned from boxplot
+        return_type : str
+            return_type passed to boxplot
+        expected_keys : list-like, optional
+            group labels in subplot case. If not passed,
+            the function checks assuming boxplot uses single ax
+        check_ax_title : bool
+            Whether to check the ax.title is the same as expected_key
+            Intended to be checked by calling from ``boxplot``.
+            Normal ``plot`` doesn't attach ``ax.title``, it must be disabled.
+        """
+        from matplotlib.axes import Axes
+
+        types = {"dict": dict, "axes": Axes, "both": tuple}
+        if expected_keys is None:
+            # should be fixed when the returning default is changed
+            if return_type is None:
+                return_type = "dict"
+
+            assert isinstance(returned, types[return_type])
+            if return_type == "both":
+                assert isinstance(returned.ax, Axes)
+                assert isinstance(returned.lines, dict)
+        else:
+            # should be fixed when the returning default is changed
+            if return_type is None:
+                for r in self._flatten_visible(returned):
+                    assert isinstance(r, Axes)
+                return
+
+            assert isinstance(returned, Series)
+
+            assert sorted(returned.keys()) == sorted(expected_keys)
+            for key, value in returned.items():
+                assert isinstance(value, types[return_type])
+                # check returned dict has correct mapping
+                if return_type == "axes":
+                    if check_ax_title:
+                        assert value.get_title() == key
+                elif return_type == "both":
+                    if check_ax_title:
+                        assert value.ax.get_title() == key
+                    assert isinstance(value.ax, Axes)
+                    assert isinstance(value.lines, dict)
+                elif return_type == "dict":
+                    line = value["medians"][0]
+                    axes = line.axes
+                    if check_ax_title:
+                        assert axes.get_title() == key
+                else:
+                    raise AssertionError
+
+    def _check_grid_settings(self, obj, kinds, kws={}):
+        # Make sure plot defaults to rcParams['axes.grid'] setting, GH 9792
+
+        import matplotlib as mpl
+
+        def is_grid_on():
+            xticks = self.plt.gca().xaxis.get_major_ticks()
+            yticks = self.plt.gca().yaxis.get_major_ticks()
+            # for mpl 2.2.2, gridOn and gridline.get_visible disagree.
+            # for new MPL, they are the same.
+
+            if self.mpl_ge_3_1_0:
+                xoff = all(not g.gridline.get_visible() for g in xticks)
+                yoff = all(not g.gridline.get_visible() for g in yticks)
+            else:
+                xoff = all(not g.gridOn for g in xticks)
+                yoff = all(not g.gridOn for g in yticks)
+
+            return not (xoff and yoff)
+
+        spndx = 1
+        for kind in kinds:
+
+            self.plt.subplot(1, 4 * len(kinds), spndx)
+            spndx += 1
+            mpl.rc("axes", grid=False)
+            obj.plot(kind=kind, **kws)
+            assert not is_grid_on()
+
+            self.plt.subplot(1, 4 * len(kinds), spndx)
+            spndx += 1
+            mpl.rc("axes", grid=True)
+            obj.plot(kind=kind, grid=False, **kws)
+            assert not is_grid_on()
+
+            if kind not in ["pie", "hexbin", "scatter"]:
+                self.plt.subplot(1, 4 * len(kinds), spndx)
+                spndx += 1
+                mpl.rc("axes", grid=True)
+                obj.plot(kind=kind, **kws)
+                assert is_grid_on()
+
+                self.plt.subplot(1, 4 * len(kinds), spndx)
+                spndx += 1
+                mpl.rc("axes", grid=False)
+                obj.plot(kind=kind, grid=True, **kws)
+                assert is_grid_on()
+
+    def _unpack_cycler(self, rcParams, field="color"):
+        """
+        Auxiliary function for correctly unpacking cycler after MPL >= 1.5
+        """
+        return [v[field] for v in rcParams["axes.prop_cycle"]]
+
+    def get_x_axis(self, ax):
+        return ax._shared_axes["x"] if self.compat.mpl_ge_3_5_0() else ax._shared_x_axes
+
+    def get_y_axis(self, ax):
+        return ax._shared_axes["y"] if self.compat.mpl_ge_3_5_0() else ax._shared_y_axes
+
+
+def _check_plot_works(f, filterwarnings="always", default_axes=False, **kwargs):
+    """
+    Create plot and ensure that plot return object is valid.
+
+    Parameters
+    ----------
+    f : func
+        Plotting function.
+    filterwarnings : str
+        Warnings filter.
+        See https://docs.python.org/3/library/warnings.html#warning-filter
+    default_axes : bool, optional
+        If False (default):
+            - If `ax` not in `kwargs`, then create subplot(211) and plot there
+            - Create new subplot(212) and plot there as well
+            - Mind special corner case for bootstrap_plot (see `_gen_two_subplots`)
+        If True:
+            - Simply run plotting function with kwargs provided
+            - All required axes instances will be created automatically
+            - It is recommended to use it when the plotting function
+            creates multiple axes itself. It helps avoid warnings like
+            'UserWarning: To output multiple subplots,
+            the figure containing the passed axes is being cleared'
+    **kwargs
+        Keyword arguments passed to the plotting function.
+
+    Returns
+    -------
+    Plot object returned by the last plotting.
+    """
+    import matplotlib.pyplot as plt
+
+    if default_axes:
+        gen_plots = _gen_default_plot
+    else:
+        gen_plots = _gen_two_subplots
+
+    ret = None
+    with warnings.catch_warnings():
+        warnings.simplefilter(filterwarnings)
+        try:
+            fig = kwargs.get("figure", plt.gcf())
+            plt.clf()
+
+            for ret in gen_plots(f, fig, **kwargs):
+                tm.assert_is_valid_plot_return_object(ret)
+
+            with tm.ensure_clean(return_filelike=True) as path:
+                plt.savefig(path)
+
+        except Exception as err:
+            raise err
+        finally:
+            tm.close(fig)
+
+        return ret
+
+
+def _gen_default_plot(f, fig, **kwargs):
+    """
+    Create plot in a default way.
+    """
+    yield f(**kwargs)
+
+
+def _gen_two_subplots(f, fig, **kwargs):
+    """
+    Create plot on two subplots forcefully created.
+    """
+    if "ax" not in kwargs:
+        fig.add_subplot(211)
+    yield f(**kwargs)
+
+    if f is pd.plotting.bootstrap_plot:
+        assert "ax" not in kwargs
+    else:
+        kwargs["ax"] = fig.add_subplot(212)
+    yield f(**kwargs)
+
+
+def curpath():
+    pth, _ = os.path.split(os.path.abspath(__file__))
+    return pth

.venv/Lib/site-packages/pandas/tests/plotting/frame/test_frame_color.py

@@ -0,0 +1,664 @@
+""" Test cases for DataFrame.plot """
+import re
+import warnings
+
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+import pandas as pd
+from pandas import DataFrame
+import pandas._testing as tm
+from pandas.tests.plotting.common import (
+    TestPlotBase,
+    _check_plot_works,
+)
+
+pytestmark = pytest.mark.slow
+
+
+@td.skip_if_no_mpl
+class TestDataFrameColor(TestPlotBase):
+    def setup_method(self, method):
+        TestPlotBase.setup_method(self, method)
+        import matplotlib as mpl
+
+        mpl.rcdefaults()
+
+        self.tdf = tm.makeTimeDataFrame()
+        self.hexbin_df = DataFrame(
+            {
+                "A": np.random.uniform(size=20),
+                "B": np.random.uniform(size=20),
+                "C": np.arange(20) + np.random.uniform(size=20),
+            }
+        )
+
+    def test_mpl2_color_cycle_str(self):
+        # GH 15516
+        df = DataFrame(np.random.randn(10, 3), columns=["a", "b", "c"])
+        colors = ["C0", "C1", "C2", "C3", "C4", "C5", "C6", "C7", "C8", "C9"]
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter("always", "MatplotlibDeprecationWarning")
+
+            for color in colors:
+                _check_plot_works(df.plot, color=color)
+
+            # if warning is raised, check that it is the exact problematic one
+            # GH 36972
+            if w:
+                match = "Support for uppercase single-letter colors is deprecated"
+                warning_message = str(w[0].message)
+                msg = "MatplotlibDeprecationWarning related to CN colors was raised"
+                assert match not in warning_message, msg
+
+    def test_color_single_series_list(self):
+        # GH 3486
+        df = DataFrame({"A": [1, 2, 3]})
+        _check_plot_works(df.plot, color=["red"])
+
+    @pytest.mark.parametrize("color", [(1, 0, 0), (1, 0, 0, 0.5)])
+    def test_rgb_tuple_color(self, color):
+        # GH 16695
+        df = DataFrame({"x": [1, 2], "y": [3, 4]})
+        _check_plot_works(df.plot, x="x", y="y", color=color)
+
+    def test_color_empty_string(self):
+        df = DataFrame(np.random.randn(10, 2))
+        with pytest.raises(ValueError, match="Invalid color argument:"):
+            df.plot(color="")
+
+    def test_color_and_style_arguments(self):
+        df = DataFrame({"x": [1, 2], "y": [3, 4]})
+        # passing both 'color' and 'style' arguments should be allowed
+        # if there is no color symbol in the style strings:
+        ax = df.plot(color=["red", "black"], style=["-", "--"])
+        # check that the linestyles are correctly set:
+        linestyle = [line.get_linestyle() for line in ax.lines]
+        assert linestyle == ["-", "--"]
+        # check that the colors are correctly set:
+        color = [line.get_color() for line in ax.lines]
+        assert color == ["red", "black"]
+        # passing both 'color' and 'style' arguments should not be allowed
+        # if there is a color symbol in the style strings:
+        msg = (
+            "Cannot pass 'style' string with a color symbol and 'color' keyword "
+            "argument. Please use one or the other or pass 'style' without a color "
+            "symbol"
+        )
+        with pytest.raises(ValueError, match=msg):
+            df.plot(color=["red", "black"], style=["k-", "r--"])
+
+    @pytest.mark.parametrize(
+        "color, expected",
+        [
+            ("green", ["green"] * 4),
+            (["yellow", "red", "green", "blue"], ["yellow", "red", "green", "blue"]),
+        ],
+    )
+    def test_color_and_marker(self, color, expected):
+        # GH 21003
+        df = DataFrame(np.random.random((7, 4)))
+        ax = df.plot(color=color, style="d--")
+        # check colors
+        result = [i.get_color() for i in ax.lines]
+        assert result == expected
+        # check markers and linestyles
+        assert all(i.get_linestyle() == "--" for i in ax.lines)
+        assert all(i.get_marker() == "d" for i in ax.lines)
+
+    def test_bar_colors(self):
+        import matplotlib.pyplot as plt
+
+        default_colors = self._unpack_cycler(plt.rcParams)
+
+        df = DataFrame(np.random.randn(5, 5))
+        ax = df.plot.bar()
+        self._check_colors(ax.patches[::5], facecolors=default_colors[:5])
+        tm.close()
+
+        custom_colors = "rgcby"
+        ax = df.plot.bar(color=custom_colors)
+        self._check_colors(ax.patches[::5], facecolors=custom_colors)
+        tm.close()
+
+        from matplotlib import cm
+
+        # Test str -> colormap functionality
+        ax = df.plot.bar(colormap="jet")
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, 5)]
+        self._check_colors(ax.patches[::5], facecolors=rgba_colors)
+        tm.close()
+
+        # Test colormap functionality
+        ax = df.plot.bar(colormap=cm.jet)
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, 5)]
+        self._check_colors(ax.patches[::5], facecolors=rgba_colors)
+        tm.close()
+
+        ax = df.loc[:, [0]].plot.bar(color="DodgerBlue")
+        self._check_colors([ax.patches[0]], facecolors=["DodgerBlue"])
+        tm.close()
+
+        ax = df.plot(kind="bar", color="green")
+        self._check_colors(ax.patches[::5], facecolors=["green"] * 5)
+        tm.close()
+
+    def test_bar_user_colors(self):
+        df = DataFrame(
+            {"A": range(4), "B": range(1, 5), "color": ["red", "blue", "blue", "red"]}
+        )
+        # This should *only* work when `y` is specified, else
+        # we use one color per column
+        ax = df.plot.bar(y="A", color=df["color"])
+        result = [p.get_facecolor() for p in ax.patches]
+        expected = [
+            (1.0, 0.0, 0.0, 1.0),
+            (0.0, 0.0, 1.0, 1.0),
+            (0.0, 0.0, 1.0, 1.0),
+            (1.0, 0.0, 0.0, 1.0),
+        ]
+        assert result == expected
+
+    def test_if_scatterplot_colorbar_affects_xaxis_visibility(self):
+        # addressing issue #10611, to ensure colobar does not
+        # interfere with x-axis label and ticklabels with
+        # ipython inline backend.
+        random_array = np.random.random((1000, 3))
+        df = DataFrame(random_array, columns=["A label", "B label", "C label"])
+
+        ax1 = df.plot.scatter(x="A label", y="B label")
+        ax2 = df.plot.scatter(x="A label", y="B label", c="C label")
+
+        vis1 = [vis.get_visible() for vis in ax1.xaxis.get_minorticklabels()]
+        vis2 = [vis.get_visible() for vis in ax2.xaxis.get_minorticklabels()]
+        assert vis1 == vis2
+
+        vis1 = [vis.get_visible() for vis in ax1.xaxis.get_majorticklabels()]
+        vis2 = [vis.get_visible() for vis in ax2.xaxis.get_majorticklabels()]
+        assert vis1 == vis2
+
+        assert (
+            ax1.xaxis.get_label().get_visible() == ax2.xaxis.get_label().get_visible()
+        )
+
+    def test_if_hexbin_xaxis_label_is_visible(self):
+        # addressing issue #10678, to ensure colobar does not
+        # interfere with x-axis label and ticklabels with
+        # ipython inline backend.
+        random_array = np.random.random((1000, 3))
+        df = DataFrame(random_array, columns=["A label", "B label", "C label"])
+
+        ax = df.plot.hexbin("A label", "B label", gridsize=12)
+        assert all(vis.get_visible() for vis in ax.xaxis.get_minorticklabels())
+        assert all(vis.get_visible() for vis in ax.xaxis.get_majorticklabels())
+        assert ax.xaxis.get_label().get_visible()
+
+    def test_if_scatterplot_colorbars_are_next_to_parent_axes(self):
+        import matplotlib.pyplot as plt
+
+        random_array = np.random.random((1000, 3))
+        df = DataFrame(random_array, columns=["A label", "B label", "C label"])
+
+        fig, axes = plt.subplots(1, 2)
+        df.plot.scatter("A label", "B label", c="C label", ax=axes[0])
+        df.plot.scatter("A label", "B label", c="C label", ax=axes[1])
+        plt.tight_layout()
+
+        points = np.array([ax.get_position().get_points() for ax in fig.axes])
+        axes_x_coords = points[:, :, 0]
+        parent_distance = axes_x_coords[1, :] - axes_x_coords[0, :]
+        colorbar_distance = axes_x_coords[3, :] - axes_x_coords[2, :]
+        assert np.isclose(parent_distance, colorbar_distance, atol=1e-7).all()
+
+    @pytest.mark.parametrize("cmap", [None, "Greys"])
+    def test_scatter_with_c_column_name_with_colors(self, cmap):
+        # https://github.com/pandas-dev/pandas/issues/34316
+        df = DataFrame(
+            [[5.1, 3.5], [4.9, 3.0], [7.0, 3.2], [6.4, 3.2], [5.9, 3.0]],
+            columns=["length", "width"],
+        )
+        df["species"] = ["r", "r", "g", "g", "b"]
+        ax = df.plot.scatter(x=0, y=1, c="species", cmap=cmap)
+        assert ax.collections[0].colorbar is None
+
+    def test_scatter_colors(self):
+        df = DataFrame({"a": [1, 2, 3], "b": [1, 2, 3], "c": [1, 2, 3]})
+        with pytest.raises(TypeError, match="Specify exactly one of `c` and `color`"):
+            df.plot.scatter(x="a", y="b", c="c", color="green")
+
+        default_colors = self._unpack_cycler(self.plt.rcParams)
+
+        ax = df.plot.scatter(x="a", y="b", c="c")
+        tm.assert_numpy_array_equal(
+            ax.collections[0].get_facecolor()[0],
+            np.array(self.colorconverter.to_rgba(default_colors[0])),
+        )
+
+        ax = df.plot.scatter(x="a", y="b", color="white")
+        tm.assert_numpy_array_equal(
+            ax.collections[0].get_facecolor()[0],
+            np.array([1, 1, 1, 1], dtype=np.float64),
+        )
+
+    def test_scatter_colorbar_different_cmap(self):
+        # GH 33389
+        import matplotlib.pyplot as plt
+
+        df = DataFrame({"x": [1, 2, 3], "y": [1, 3, 2], "c": [1, 2, 3]})
+        df["x2"] = df["x"] + 1
+
+        fig, ax = plt.subplots()
+        df.plot("x", "y", c="c", kind="scatter", cmap="cividis", ax=ax)
+        df.plot("x2", "y", c="c", kind="scatter", cmap="magma", ax=ax)
+
+        assert ax.collections[0].cmap.name == "cividis"
+        assert ax.collections[1].cmap.name == "magma"
+
+    def test_line_colors(self):
+        from matplotlib import cm
+
+        custom_colors = "rgcby"
+        df = DataFrame(np.random.randn(5, 5))
+
+        ax = df.plot(color=custom_colors)
+        self._check_colors(ax.get_lines(), linecolors=custom_colors)
+
+        tm.close()
+
+        ax2 = df.plot(color=custom_colors)
+        lines2 = ax2.get_lines()
+
+        for l1, l2 in zip(ax.get_lines(), lines2):
+            assert l1.get_color() == l2.get_color()
+
+        tm.close()
+
+        ax = df.plot(colormap="jet")
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, len(df))]
+        self._check_colors(ax.get_lines(), linecolors=rgba_colors)
+        tm.close()
+
+        ax = df.plot(colormap=cm.jet)
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, len(df))]
+        self._check_colors(ax.get_lines(), linecolors=rgba_colors)
+        tm.close()
+
+        # make color a list if plotting one column frame
+        # handles cases like df.plot(color='DodgerBlue')
+        ax = df.loc[:, [0]].plot(color="DodgerBlue")
+        self._check_colors(ax.lines, linecolors=["DodgerBlue"])
+
+        ax = df.plot(color="red")
+        self._check_colors(ax.get_lines(), linecolors=["red"] * 5)
+        tm.close()
+
+        # GH 10299
+        custom_colors = ["#FF0000", "#0000FF", "#FFFF00", "#000000", "#FFFFFF"]
+        ax = df.plot(color=custom_colors)
+        self._check_colors(ax.get_lines(), linecolors=custom_colors)
+        tm.close()
+
+    def test_dont_modify_colors(self):
+        colors = ["r", "g", "b"]
+        DataFrame(np.random.rand(10, 2)).plot(color=colors)
+        assert len(colors) == 3
+
+    def test_line_colors_and_styles_subplots(self):
+        # GH 9894
+        from matplotlib import cm
+
+        default_colors = self._unpack_cycler(self.plt.rcParams)
+
+        df = DataFrame(np.random.randn(5, 5))
+
+        axes = df.plot(subplots=True)
+        for ax, c in zip(axes, list(default_colors)):
+            self._check_colors(ax.get_lines(), linecolors=[c])
+        tm.close()
+
+        # single color char
+        axes = df.plot(subplots=True, color="k")
+        for ax in axes:
+            self._check_colors(ax.get_lines(), linecolors=["k"])
+        tm.close()
+
+        # single color str
+        axes = df.plot(subplots=True, color="green")
+        for ax in axes:
+            self._check_colors(ax.get_lines(), linecolors=["green"])
+        tm.close()
+
+        custom_colors = "rgcby"
+        axes = df.plot(color=custom_colors, subplots=True)
+        for ax, c in zip(axes, list(custom_colors)):
+            self._check_colors(ax.get_lines(), linecolors=[c])
+        tm.close()
+
+        axes = df.plot(color=list(custom_colors), subplots=True)
+        for ax, c in zip(axes, list(custom_colors)):
+            self._check_colors(ax.get_lines(), linecolors=[c])
+        tm.close()
+
+        # GH 10299
+        custom_colors = ["#FF0000", "#0000FF", "#FFFF00", "#000000", "#FFFFFF"]
+        axes = df.plot(color=custom_colors, subplots=True)
+        for ax, c in zip(axes, list(custom_colors)):
+            self._check_colors(ax.get_lines(), linecolors=[c])
+        tm.close()
+
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, len(df))]
+        for cmap in ["jet", cm.jet]:
+            axes = df.plot(colormap=cmap, subplots=True)
+            for ax, c in zip(axes, rgba_colors):
+                self._check_colors(ax.get_lines(), linecolors=[c])
+            tm.close()
+
+        # make color a list if plotting one column frame
+        # handles cases like df.plot(color='DodgerBlue')
+        axes = df.loc[:, [0]].plot(color="DodgerBlue", subplots=True)
+        self._check_colors(axes[0].lines, linecolors=["DodgerBlue"])
+
+        # single character style
+        axes = df.plot(style="r", subplots=True)
+        for ax in axes:
+            self._check_colors(ax.get_lines(), linecolors=["r"])
+        tm.close()
+
+        # list of styles
+        styles = list("rgcby")
+        axes = df.plot(style=styles, subplots=True)
+        for ax, c in zip(axes, styles):
+            self._check_colors(ax.get_lines(), linecolors=[c])
+        tm.close()
+
+    def test_area_colors(self):
+        from matplotlib import cm
+        from matplotlib.collections import PolyCollection
+
+        custom_colors = "rgcby"
+        df = DataFrame(np.random.rand(5, 5))
+
+        ax = df.plot.area(color=custom_colors)
+        self._check_colors(ax.get_lines(), linecolors=custom_colors)
+        poly = [o for o in ax.get_children() if isinstance(o, PolyCollection)]
+        self._check_colors(poly, facecolors=custom_colors)
+
+        handles, labels = ax.get_legend_handles_labels()
+        self._check_colors(handles, facecolors=custom_colors)
+
+        for h in handles:
+            assert h.get_alpha() is None
+        tm.close()
+
+        ax = df.plot.area(colormap="jet")
+        jet_colors = [cm.jet(n) for n in np.linspace(0, 1, len(df))]
+        self._check_colors(ax.get_lines(), linecolors=jet_colors)
+        poly = [o for o in ax.get_children() if isinstance(o, PolyCollection)]
+        self._check_colors(poly, facecolors=jet_colors)
+
+        handles, labels = ax.get_legend_handles_labels()
+        self._check_colors(handles, facecolors=jet_colors)
+        for h in handles:
+            assert h.get_alpha() is None
+        tm.close()
+
+        # When stacked=False, alpha is set to 0.5
+        ax = df.plot.area(colormap=cm.jet, stacked=False)
+        self._check_colors(ax.get_lines(), linecolors=jet_colors)
+        poly = [o for o in ax.get_children() if isinstance(o, PolyCollection)]
+        jet_with_alpha = [(c[0], c[1], c[2], 0.5) for c in jet_colors]
+        self._check_colors(poly, facecolors=jet_with_alpha)
+
+        handles, labels = ax.get_legend_handles_labels()
+        linecolors = jet_with_alpha
+        self._check_colors(handles[: len(jet_colors)], linecolors=linecolors)
+        for h in handles:
+            assert h.get_alpha() == 0.5
+
+    def test_hist_colors(self):
+        default_colors = self._unpack_cycler(self.plt.rcParams)
+
+        df = DataFrame(np.random.randn(5, 5))
+        ax = df.plot.hist()
+        self._check_colors(ax.patches[::10], facecolors=default_colors[:5])
+        tm.close()
+
+        custom_colors = "rgcby"
+        ax = df.plot.hist(color=custom_colors)
+        self._check_colors(ax.patches[::10], facecolors=custom_colors)
+        tm.close()
+
+        from matplotlib import cm
+
+        # Test str -> colormap functionality
+        ax = df.plot.hist(colormap="jet")
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, 5)]
+        self._check_colors(ax.patches[::10], facecolors=rgba_colors)
+        tm.close()
+
+        # Test colormap functionality
+        ax = df.plot.hist(colormap=cm.jet)
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, 5)]
+        self._check_colors(ax.patches[::10], facecolors=rgba_colors)
+        tm.close()
+
+        ax = df.loc[:, [0]].plot.hist(color="DodgerBlue")
+        self._check_colors([ax.patches[0]], facecolors=["DodgerBlue"])
+
+        ax = df.plot(kind="hist", color="green")
+        self._check_colors(ax.patches[::10], facecolors=["green"] * 5)
+        tm.close()
+
+    @td.skip_if_no_scipy
+    def test_kde_colors(self):
+        from matplotlib import cm
+
+        custom_colors = "rgcby"
+        df = DataFrame(np.random.rand(5, 5))
+
+        ax = df.plot.kde(color=custom_colors)
+        self._check_colors(ax.get_lines(), linecolors=custom_colors)
+        tm.close()
+
+        ax = df.plot.kde(colormap="jet")
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, len(df))]
+        self._check_colors(ax.get_lines(), linecolors=rgba_colors)
+        tm.close()
+
+        ax = df.plot.kde(colormap=cm.jet)
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, len(df))]
+        self._check_colors(ax.get_lines(), linecolors=rgba_colors)
+
+    @td.skip_if_no_scipy
+    def test_kde_colors_and_styles_subplots(self):
+        from matplotlib import cm
+
+        default_colors = self._unpack_cycler(self.plt.rcParams)
+
+        df = DataFrame(np.random.randn(5, 5))
+
+        axes = df.plot(kind="kde", subplots=True)
+        for ax, c in zip(axes, list(default_colors)):
+            self._check_colors(ax.get_lines(), linecolors=[c])
+        tm.close()
+
+        # single color char
+        axes = df.plot(kind="kde", color="k", subplots=True)
+        for ax in axes:
+            self._check_colors(ax.get_lines(), linecolors=["k"])
+        tm.close()
+
+        # single color str
+        axes = df.plot(kind="kde", color="red", subplots=True)
+        for ax in axes:
+            self._check_colors(ax.get_lines(), linecolors=["red"])
+        tm.close()
+
+        custom_colors = "rgcby"
+        axes = df.plot(kind="kde", color=custom_colors, subplots=True)
+        for ax, c in zip(axes, list(custom_colors)):
+            self._check_colors(ax.get_lines(), linecolors=[c])
+        tm.close()
+
+        rgba_colors = [cm.jet(n) for n in np.linspace(0, 1, len(df))]
+        for cmap in ["jet", cm.jet]:
+            axes = df.plot(kind="kde", colormap=cmap, subplots=True)
+            for ax, c in zip(axes, rgba_colors):
+                self._check_colors(ax.get_lines(), linecolors=[c])
+            tm.close()
+
+        # make color a list if plotting one column frame
+        # handles cases like df.plot(color='DodgerBlue')
+        axes = df.loc[:, [0]].plot(kind="kde", color="DodgerBlue", subplots=True)
+        self._check_colors(axes[0].lines, linecolors=["DodgerBlue"])
+
+        # single character style
+        axes = df.plot(kind="kde", style="r", subplots=True)
+        for ax in axes:
+            self._check_colors(ax.get_lines(), linecolors=["r"])
+        tm.close()
+
+        # list of styles
+        styles = list("rgcby")
+        axes = df.plot(kind="kde", style=styles, subplots=True)
+        for ax, c in zip(axes, styles):
+            self._check_colors(ax.get_lines(), linecolors=[c])
+        tm.close()
+
+    def test_boxplot_colors(self):
+        def _check_colors(bp, box_c, whiskers_c, medians_c, caps_c="k", fliers_c=None):
+            # TODO: outside this func?
+            if fliers_c is None:
+                fliers_c = "k"
+            self._check_colors(bp["boxes"], linecolors=[box_c] * len(bp["boxes"]))
+            self._check_colors(
+                bp["whiskers"], linecolors=[whiskers_c] * len(bp["whiskers"])
+            )
+            self._check_colors(
+                bp["medians"], linecolors=[medians_c] * len(bp["medians"])
+            )
+            self._check_colors(bp["fliers"], linecolors=[fliers_c] * len(bp["fliers"]))
+            self._check_colors(bp["caps"], linecolors=[caps_c] * len(bp["caps"]))
+
+        default_colors = self._unpack_cycler(self.plt.rcParams)
+
+        df = DataFrame(np.random.randn(5, 5))
+        bp = df.plot.box(return_type="dict")
+        _check_colors(
+            bp,
+            default_colors[0],
+            default_colors[0],
+            default_colors[2],
+            default_colors[0],
+        )
+        tm.close()
+
+        dict_colors = {
+            "boxes": "#572923",
+            "whiskers": "#982042",
+            "medians": "#804823",
+            "caps": "#123456",
+        }
+        bp = df.plot.box(color=dict_colors, sym="r+", return_type="dict")
+        _check_colors(
+            bp,
+            dict_colors["boxes"],
+            dict_colors["whiskers"],
+            dict_colors["medians"],
+            dict_colors["caps"],
+            "r",
+        )
+        tm.close()
+
+        # partial colors
+        dict_colors = {"whiskers": "c", "medians": "m"}
+        bp = df.plot.box(color=dict_colors, return_type="dict")
+        _check_colors(bp, default_colors[0], "c", "m", default_colors[0])
+        tm.close()
+
+        from matplotlib import cm
+
+        # Test str -> colormap functionality
+        bp = df.plot.box(colormap="jet", return_type="dict")
+        jet_colors = [cm.jet(n) for n in np.linspace(0, 1, 3)]
+        _check_colors(bp, jet_colors[0], jet_colors[0], jet_colors[2], jet_colors[0])
+        tm.close()
+
+        # Test colormap functionality
+        bp = df.plot.box(colormap=cm.jet, return_type="dict")
+        _check_colors(bp, jet_colors[0], jet_colors[0], jet_colors[2], jet_colors[0])
+        tm.close()
+
+        # string color is applied to all artists except fliers
+        bp = df.plot.box(color="DodgerBlue", return_type="dict")
+        _check_colors(bp, "DodgerBlue", "DodgerBlue", "DodgerBlue", "DodgerBlue")
+
+        # tuple is also applied to all artists except fliers
+        bp = df.plot.box(color=(0, 1, 0), sym="#123456", return_type="dict")
+        _check_colors(bp, (0, 1, 0), (0, 1, 0), (0, 1, 0), (0, 1, 0), "#123456")
+
+        msg = re.escape(
+            "color dict contains invalid key 'xxxx'. The key must be either "
+            "['boxes', 'whiskers', 'medians', 'caps']"
+        )
+        with pytest.raises(ValueError, match=msg):
+            # Color contains invalid key results in ValueError
+            df.plot.box(color={"boxes": "red", "xxxx": "blue"})
+
+    def test_default_color_cycle(self):
+        import cycler
+        import matplotlib.pyplot as plt
+
+        colors = list("rgbk")
+        plt.rcParams["axes.prop_cycle"] = cycler.cycler("color", colors)
+
+        df = DataFrame(np.random.randn(5, 3))
+        ax = df.plot()
+
+        expected = self._unpack_cycler(plt.rcParams)[:3]
+        self._check_colors(ax.get_lines(), linecolors=expected)
+
+    def test_no_color_bar(self):
+        df = self.hexbin_df
+        ax = df.plot.hexbin(x="A", y="B", colorbar=None)
+        assert ax.collections[0].colorbar is None
+
+    def test_mixing_cmap_and_colormap_raises(self):
+        df = self.hexbin_df
+        msg = "Only specify one of `cmap` and `colormap`"
+        with pytest.raises(TypeError, match=msg):
+            df.plot.hexbin(x="A", y="B", cmap="YlGn", colormap="BuGn")
+
+    def test_passed_bar_colors(self):
+        import matplotlib as mpl
+
+        color_tuples = [(0.9, 0, 0, 1), (0, 0.9, 0, 1), (0, 0, 0.9, 1)]
+        colormap = mpl.colors.ListedColormap(color_tuples)
+        barplot = DataFrame([[1, 2, 3]]).plot(kind="bar", cmap=colormap)
+        assert color_tuples == [c.get_facecolor() for c in barplot.patches]
+
+    def test_rcParams_bar_colors(self):
+        import matplotlib as mpl
+
+        color_tuples = [(0.9, 0, 0, 1), (0, 0.9, 0, 1), (0, 0, 0.9, 1)]
+        with mpl.rc_context(rc={"axes.prop_cycle": mpl.cycler("color", color_tuples)}):
+            barplot = DataFrame([[1, 2, 3]]).plot(kind="bar")
+        assert color_tuples == [c.get_facecolor() for c in barplot.patches]
+
+    def test_colors_of_columns_with_same_name(self):
+        # ISSUE 11136 -> https://github.com/pandas-dev/pandas/issues/11136
+        # Creating a DataFrame with duplicate column labels and testing colors of them.
+        df = DataFrame({"b": [0, 1, 0], "a": [1, 2, 3]})
+        df1 = DataFrame({"a": [2, 4, 6]})
+        df_concat = pd.concat([df, df1], axis=1)
+        result = df_concat.plot()
+        for legend, line in zip(result.get_legend().legendHandles, result.lines):
+            assert legend.get_color() == line.get_color()
+
+    def test_invalid_colormap(self):
+        df = DataFrame(np.random.randn(3, 2), columns=["A", "B"])
+        msg = "'invalid_colormap' is not a valid value for name; supported values are "
+        with pytest.raises(ValueError, match=msg):
+            df.plot(colormap="invalid_colormap")

.venv/Lib/site-packages/pandas/tests/plotting/frame/test_frame_groupby.py

@@ -0,0 +1,92 @@
+""" Test cases for DataFrame.plot """
+
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+from pandas import DataFrame
+import pandas._testing as tm
+from pandas.tests.plotting.common import TestPlotBase
+
+pytestmark = pytest.mark.slow
+
+
+@td.skip_if_no_mpl
+class TestDataFramePlotsGroupby(TestPlotBase):
+    def setup_method(self, method):
+        TestPlotBase.setup_method(self, method)
+        import matplotlib as mpl
+
+        mpl.rcdefaults()
+
+        self.tdf = tm.makeTimeDataFrame()
+        self.hexbin_df = DataFrame(
+            {
+                "A": np.random.uniform(size=20),
+                "B": np.random.uniform(size=20),
+                "C": np.arange(20) + np.random.uniform(size=20),
+            }
+        )
+
+    def _assert_ytickslabels_visibility(self, axes, expected):
+        for ax, exp in zip(axes, expected):
+            self._check_visible(ax.get_yticklabels(), visible=exp)
+
+    def _assert_xtickslabels_visibility(self, axes, expected):
+        for ax, exp in zip(axes, expected):
+            self._check_visible(ax.get_xticklabels(), visible=exp)
+
+    @pytest.mark.parametrize(
+        "kwargs, expected",
+        [
+            # behavior without keyword
+            ({}, [True, False, True, False]),
+            # set sharey=True should be identical
+            ({"sharey": True}, [True, False, True, False]),
+            # sharey=False, all yticklabels should be visible
+            ({"sharey": False}, [True, True, True, True]),
+        ],
+    )
+    def test_groupby_boxplot_sharey(self, kwargs, expected):
+        # https://github.com/pandas-dev/pandas/issues/20968
+        # sharey can now be switched check whether the right
+        # pair of axes is turned on or off
+        df = DataFrame(
+            {
+                "a": [-1.43, -0.15, -3.70, -1.43, -0.14],
+                "b": [0.56, 0.84, 0.29, 0.56, 0.85],
+                "c": [0, 1, 2, 3, 1],
+            },
+            index=[0, 1, 2, 3, 4],
+        )
+        axes = df.groupby("c").boxplot(**kwargs)
+        self._assert_ytickslabels_visibility(axes, expected)
+
+    @pytest.mark.parametrize(
+        "kwargs, expected",
+        [
+            # behavior without keyword
+            ({}, [True, True, True, True]),
+            # set sharex=False should be identical
+            ({"sharex": False}, [True, True, True, True]),
+            # sharex=True, xticklabels should be visible
+            # only for bottom plots
+            ({"sharex": True}, [False, False, True, True]),
+        ],
+    )
+    def test_groupby_boxplot_sharex(self, kwargs, expected):
+        # https://github.com/pandas-dev/pandas/issues/20968
+        # sharex can now be switched check whether the right
+        # pair of axes is turned on or off
+
+        df = DataFrame(
+            {
+                "a": [-1.43, -0.15, -3.70, -1.43, -0.14],
+                "b": [0.56, 0.84, 0.29, 0.56, 0.85],
+                "c": [0, 1, 2, 3, 1],
+            },
+            index=[0, 1, 2, 3, 4],
+        )
+        axes = df.groupby("c").boxplot(**kwargs)
+        self._assert_xtickslabels_visibility(axes, expected)

.venv/Lib/site-packages/pandas/tests/plotting/frame/test_frame_legend.py

@@ -0,0 +1,195 @@
+import numpy as np
+import pytest
+
+from pandas import (
+    DataFrame,
+    date_range,
+)
+from pandas.tests.plotting.common import TestPlotBase
+
+pytestmark = pytest.mark.slow
+
+
+class TestFrameLegend(TestPlotBase):
+    @pytest.mark.xfail(
+        reason=(
+            "Open bug in matplotlib "
+            "https://github.com/matplotlib/matplotlib/issues/11357"
+        )
+    )
+    def test_mixed_yerr(self):
+        # https://github.com/pandas-dev/pandas/issues/39522
+        from matplotlib.collections import LineCollection
+        from matplotlib.lines import Line2D
+
+        df = DataFrame([{"x": 1, "a": 1, "b": 1}, {"x": 2, "a": 2, "b": 3}])
+
+        ax = df.plot("x", "a", c="orange", yerr=0.1, label="orange")
+        df.plot("x", "b", c="blue", yerr=None, ax=ax, label="blue")
+
+        legend = ax.get_legend()
+        result_handles = legend.legendHandles
+
+        assert isinstance(result_handles[0], LineCollection)
+        assert isinstance(result_handles[1], Line2D)
+
+    def test_legend_false(self):
+        # https://github.com/pandas-dev/pandas/issues/40044
+        df = DataFrame({"a": [1, 1], "b": [2, 3]})
+        df2 = DataFrame({"d": [2.5, 2.5]})
+
+        ax = df.plot(legend=True, color={"a": "blue", "b": "green"}, secondary_y="b")
+        df2.plot(legend=True, color={"d": "red"}, ax=ax)
+        legend = ax.get_legend()
+        result = [handle.get_color() for handle in legend.legendHandles]
+        expected = ["blue", "green", "red"]
+        assert result == expected
+
+    def test_df_legend_labels(self):
+        kinds = ["line", "bar", "barh", "kde", "area", "hist"]
+        df = DataFrame(np.random.rand(3, 3), columns=["a", "b", "c"])
+        df2 = DataFrame(np.random.rand(3, 3), columns=["d", "e", "f"])
+        df3 = DataFrame(np.random.rand(3, 3), columns=["g", "h", "i"])
+        df4 = DataFrame(np.random.rand(3, 3), columns=["j", "k", "l"])
+
+        for kind in kinds:
+
+            ax = df.plot(kind=kind, legend=True)
+            self._check_legend_labels(ax, labels=df.columns)
+
+            ax = df2.plot(kind=kind, legend=False, ax=ax)
+            self._check_legend_labels(ax, labels=df.columns)
+
+            ax = df3.plot(kind=kind, legend=True, ax=ax)
+            self._check_legend_labels(ax, labels=df.columns.union(df3.columns))
+
+            ax = df4.plot(kind=kind, legend="reverse", ax=ax)
+            expected = list(df.columns.union(df3.columns)) + list(reversed(df4.columns))
+            self._check_legend_labels(ax, labels=expected)
+
+        # Secondary Y
+        ax = df.plot(legend=True, secondary_y="b")
+        self._check_legend_labels(ax, labels=["a", "b (right)", "c"])
+        ax = df2.plot(legend=False, ax=ax)
+        self._check_legend_labels(ax, labels=["a", "b (right)", "c"])
+        ax = df3.plot(kind="bar", legend=True, secondary_y="h", ax=ax)
+        self._check_legend_labels(
+            ax, labels=["a", "b (right)", "c", "g", "h (right)", "i"]
+        )
+
+        # Time Series
+        ind = date_range("1/1/2014", periods=3)
+        df = DataFrame(np.random.randn(3, 3), columns=["a", "b", "c"], index=ind)
+        df2 = DataFrame(np.random.randn(3, 3), columns=["d", "e", "f"], index=ind)
+        df3 = DataFrame(np.random.randn(3, 3), columns=["g", "h", "i"], index=ind)
+        ax = df.plot(legend=True, secondary_y="b")
+        self._check_legend_labels(ax, labels=["a", "b (right)", "c"])
+        ax = df2.plot(legend=False, ax=ax)
+        self._check_legend_labels(ax, labels=["a", "b (right)", "c"])
+        ax = df3.plot(legend=True, ax=ax)
+        self._check_legend_labels(ax, labels=["a", "b (right)", "c", "g", "h", "i"])
+
+        # scatter
+        ax = df.plot.scatter(x="a", y="b", label="data1")
+        self._check_legend_labels(ax, labels=["data1"])
+        ax = df2.plot.scatter(x="d", y="e", legend=False, label="data2", ax=ax)
+        self._check_legend_labels(ax, labels=["data1"])
+        ax = df3.plot.scatter(x="g", y="h", label="data3", ax=ax)
+        self._check_legend_labels(ax, labels=["data1", "data3"])
+
+        # ensure label args pass through and
+        # index name does not mutate
+        # column names don't mutate
+        df5 = df.set_index("a")
+        ax = df5.plot(y="b")
+        self._check_legend_labels(ax, labels=["b"])
+        ax = df5.plot(y="b", label="LABEL_b")
+        self._check_legend_labels(ax, labels=["LABEL_b"])
+        self._check_text_labels(ax.xaxis.get_label(), "a")
+        ax = df5.plot(y="c", label="LABEL_c", ax=ax)
+        self._check_legend_labels(ax, labels=["LABEL_b", "LABEL_c"])
+        assert df5.columns.tolist() == ["b", "c"]
+
+    def test_missing_marker_multi_plots_on_same_ax(self):
+        # GH 18222
+        df = DataFrame(data=[[1, 1, 1, 1], [2, 2, 4, 8]], columns=["x", "r", "g", "b"])
+        fig, ax = self.plt.subplots(nrows=1, ncols=3)
+        # Left plot
+        df.plot(x="x", y="r", linewidth=0, marker="o", color="r", ax=ax[0])
+        df.plot(x="x", y="g", linewidth=1, marker="x", color="g", ax=ax[0])
+        df.plot(x="x", y="b", linewidth=1, marker="o", color="b", ax=ax[0])
+        self._check_legend_labels(ax[0], labels=["r", "g", "b"])
+        self._check_legend_marker(ax[0], expected_markers=["o", "x", "o"])
+        # Center plot
+        df.plot(x="x", y="b", linewidth=1, marker="o", color="b", ax=ax[1])
+        df.plot(x="x", y="r", linewidth=0, marker="o", color="r", ax=ax[1])
+        df.plot(x="x", y="g", linewidth=1, marker="x", color="g", ax=ax[1])
+        self._check_legend_labels(ax[1], labels=["b", "r", "g"])
+        self._check_legend_marker(ax[1], expected_markers=["o", "o", "x"])
+        # Right plot
+        df.plot(x="x", y="g", linewidth=1, marker="x", color="g", ax=ax[2])
+        df.plot(x="x", y="b", linewidth=1, marker="o", color="b", ax=ax[2])
+        df.plot(x="x", y="r", linewidth=0, marker="o", color="r", ax=ax[2])
+        self._check_legend_labels(ax[2], labels=["g", "b", "r"])
+        self._check_legend_marker(ax[2], expected_markers=["x", "o", "o"])
+
+    def test_legend_name(self):
+        multi = DataFrame(
+            np.random.randn(4, 4),
+            columns=[np.array(["a", "a", "b", "b"]), np.array(["x", "y", "x", "y"])],
+        )
+        multi.columns.names = ["group", "individual"]
+
+        ax = multi.plot()
+        leg_title = ax.legend_.get_title()
+        self._check_text_labels(leg_title, "group,individual")
+
+        df = DataFrame(np.random.randn(5, 5))
+        ax = df.plot(legend=True, ax=ax)
+        leg_title = ax.legend_.get_title()
+        self._check_text_labels(leg_title, "group,individual")
+
+        df.columns.name = "new"
+        ax = df.plot(legend=False, ax=ax)
+        leg_title = ax.legend_.get_title()
+        self._check_text_labels(leg_title, "group,individual")
+
+        ax = df.plot(legend=True, ax=ax)
+        leg_title = ax.legend_.get_title()
+        self._check_text_labels(leg_title, "new")
+
+    def test_no_legend(self):
+        kinds = ["line", "bar", "barh", "kde", "area", "hist"]
+        df = DataFrame(np.random.rand(3, 3), columns=["a", "b", "c"])
+
+        for kind in kinds:
+            ax = df.plot(kind=kind, legend=False)
+            self._check_legend_labels(ax, visible=False)
+
+    def test_missing_markers_legend(self):
+        # 14958
+        df = DataFrame(np.random.randn(8, 3), columns=["A", "B", "C"])
+        ax = df.plot(y=["A"], marker="x", linestyle="solid")
+        df.plot(y=["B"], marker="o", linestyle="dotted", ax=ax)
+        df.plot(y=["C"], marker="<", linestyle="dotted", ax=ax)
+
+        self._check_legend_labels(ax, labels=["A", "B", "C"])
+        self._check_legend_marker(ax, expected_markers=["x", "o", "<"])
+
+    def test_missing_markers_legend_using_style(self):
+        # 14563
+        df = DataFrame(
+            {
+                "A": [1, 2, 3, 4, 5, 6],
+                "B": [2, 4, 1, 3, 2, 4],
+                "C": [3, 3, 2, 6, 4, 2],
+                "X": [1, 2, 3, 4, 5, 6],
+            }
+        )
+
+        fig, ax = self.plt.subplots()
+        for kind in "ABC":
+            df.plot("X", kind, label=kind, ax=ax, style=".")
+
+        self._check_legend_labels(ax, labels=["A", "B", "C"])
+        self._check_legend_marker(ax, expected_markers=[".", ".", "."])

.venv/Lib/site-packages/pandas/tests/plotting/frame/test_frame_subplots.py

@@ -0,0 +1,687 @@
+""" Test cases for DataFrame.plot """
+
+import string
+import warnings
+
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+import pandas as pd
+from pandas import (
+    DataFrame,
+    Series,
+    date_range,
+)
+import pandas._testing as tm
+from pandas.tests.plotting.common import TestPlotBase
+
+from pandas.io.formats.printing import pprint_thing
+
+pytestmark = pytest.mark.slow
+
+
+@td.skip_if_no_mpl
+class TestDataFramePlotsSubplots(TestPlotBase):
+    def setup_method(self, method):
+        TestPlotBase.setup_method(self, method)
+        import matplotlib as mpl
+
+        mpl.rcdefaults()
+
+        self.tdf = tm.makeTimeDataFrame()
+        self.hexbin_df = DataFrame(
+            {
+                "A": np.random.uniform(size=20),
+                "B": np.random.uniform(size=20),
+                "C": np.arange(20) + np.random.uniform(size=20),
+            }
+        )
+
+    def test_subplots(self):
+        df = DataFrame(np.random.rand(10, 3), index=list(string.ascii_letters[:10]))
+
+        for kind in ["bar", "barh", "line", "area"]:
+            axes = df.plot(kind=kind, subplots=True, sharex=True, legend=True)
+            self._check_axes_shape(axes, axes_num=3, layout=(3, 1))
+            assert axes.shape == (3,)
+
+            for ax, column in zip(axes, df.columns):
+                self._check_legend_labels(ax, labels=[pprint_thing(column)])
+
+            for ax in axes[:-2]:
+                self._check_visible(ax.xaxis)  # xaxis must be visible for grid
+                self._check_visible(ax.get_xticklabels(), visible=False)
+                if not (kind == "bar" and self.mpl_ge_3_1_0):
+                    # change https://github.com/pandas-dev/pandas/issues/26714
+                    self._check_visible(ax.get_xticklabels(minor=True), visible=False)
+                self._check_visible(ax.xaxis.get_label(), visible=False)
+                self._check_visible(ax.get_yticklabels())
+
+            self._check_visible(axes[-1].xaxis)
+            self._check_visible(axes[-1].get_xticklabels())
+            self._check_visible(axes[-1].get_xticklabels(minor=True))
+            self._check_visible(axes[-1].xaxis.get_label())
+            self._check_visible(axes[-1].get_yticklabels())
+
+            axes = df.plot(kind=kind, subplots=True, sharex=False)
+            for ax in axes:
+                self._check_visible(ax.xaxis)
+                self._check_visible(ax.get_xticklabels())
+                self._check_visible(ax.get_xticklabels(minor=True))
+                self._check_visible(ax.xaxis.get_label())
+                self._check_visible(ax.get_yticklabels())
+
+            axes = df.plot(kind=kind, subplots=True, legend=False)
+            for ax in axes:
+                assert ax.get_legend() is None
+
+    def test_subplots_timeseries(self):
+        idx = date_range(start="2014-07-01", freq="M", periods=10)
+        df = DataFrame(np.random.rand(10, 3), index=idx)
+
+        for kind in ["line", "area"]:
+            axes = df.plot(kind=kind, subplots=True, sharex=True)
+            self._check_axes_shape(axes, axes_num=3, layout=(3, 1))
+
+            for ax in axes[:-2]:
+                # GH 7801
+                self._check_visible(ax.xaxis)  # xaxis must be visible for grid
+                self._check_visible(ax.get_xticklabels(), visible=False)
+                self._check_visible(ax.get_xticklabels(minor=True), visible=False)
+                self._check_visible(ax.xaxis.get_label(), visible=False)
+                self._check_visible(ax.get_yticklabels())
+
+            self._check_visible(axes[-1].xaxis)
+            self._check_visible(axes[-1].get_xticklabels())
+            self._check_visible(axes[-1].get_xticklabels(minor=True))
+            self._check_visible(axes[-1].xaxis.get_label())
+            self._check_visible(axes[-1].get_yticklabels())
+            self._check_ticks_props(axes, xrot=0)
+
+            axes = df.plot(kind=kind, subplots=True, sharex=False, rot=45, fontsize=7)
+            for ax in axes:
+                self._check_visible(ax.xaxis)
+                self._check_visible(ax.get_xticklabels())
+                self._check_visible(ax.get_xticklabels(minor=True))
+                self._check_visible(ax.xaxis.get_label())
+                self._check_visible(ax.get_yticklabels())
+                self._check_ticks_props(ax, xlabelsize=7, xrot=45, ylabelsize=7)
+
+    def test_subplots_timeseries_y_axis(self):
+        # GH16953
+        data = {
+            "numeric": np.array([1, 2, 5]),
+            "timedelta": [
+                pd.Timedelta(-10, unit="s"),
+                pd.Timedelta(10, unit="m"),
+                pd.Timedelta(10, unit="h"),
+            ],
+            "datetime_no_tz": [
+                pd.to_datetime("2017-08-01 00:00:00"),
+                pd.to_datetime("2017-08-01 02:00:00"),
+                pd.to_datetime("2017-08-02 00:00:00"),
+            ],
+            "datetime_all_tz": [
+                pd.to_datetime("2017-08-01 00:00:00", utc=True),
+                pd.to_datetime("2017-08-01 02:00:00", utc=True),
+                pd.to_datetime("2017-08-02 00:00:00", utc=True),
+            ],
+            "text": ["This", "should", "fail"],
+        }
+        testdata = DataFrame(data)
+
+        y_cols = ["numeric", "timedelta", "datetime_no_tz", "datetime_all_tz"]
+        for col in y_cols:
+            ax = testdata.plot(y=col)
+            result = ax.get_lines()[0].get_data()[1]
+            expected = testdata[col].values
+            assert (result == expected).all()
+
+        msg = "no numeric data to plot"
+        with pytest.raises(TypeError, match=msg):
+            testdata.plot(y="text")
+
+    @pytest.mark.xfail(reason="not support for period, categorical, datetime_mixed_tz")
+    def test_subplots_timeseries_y_axis_not_supported(self):
+        """
+        This test will fail for:
+            period:
+                since period isn't yet implemented in ``select_dtypes``
+                and because it will need a custom value converter +
+                tick formatter (as was done for x-axis plots)
+
+            categorical:
+                 because it will need a custom value converter +
+                 tick formatter (also doesn't work for x-axis, as of now)
+
+            datetime_mixed_tz:
+                because of the way how pandas handles ``Series`` of
+                ``datetime`` objects with different timezone,
+                generally converting ``datetime`` objects in a tz-aware
+                form could help with this problem
+        """
+        data = {
+            "numeric": np.array([1, 2, 5]),
+            "period": [
+                pd.Period("2017-08-01 00:00:00", freq="H"),
+                pd.Period("2017-08-01 02:00", freq="H"),
+                pd.Period("2017-08-02 00:00:00", freq="H"),
+            ],
+            "categorical": pd.Categorical(
+                ["c", "b", "a"], categories=["a", "b", "c"], ordered=False
+            ),
+            "datetime_mixed_tz": [
+                pd.to_datetime("2017-08-01 00:00:00", utc=True),
+                pd.to_datetime("2017-08-01 02:00:00"),
+                pd.to_datetime("2017-08-02 00:00:00"),
+            ],
+        }
+        testdata = DataFrame(data)
+        ax_period = testdata.plot(x="numeric", y="period")
+        assert (
+            ax_period.get_lines()[0].get_data()[1] == testdata["period"].values
+        ).all()
+        ax_categorical = testdata.plot(x="numeric", y="categorical")
+        assert (
+            ax_categorical.get_lines()[0].get_data()[1]
+            == testdata["categorical"].values
+        ).all()
+        ax_datetime_mixed_tz = testdata.plot(x="numeric", y="datetime_mixed_tz")
+        assert (
+            ax_datetime_mixed_tz.get_lines()[0].get_data()[1]
+            == testdata["datetime_mixed_tz"].values
+        ).all()
+
+    def test_subplots_layout_multi_column(self):
+        # GH 6667
+        df = DataFrame(np.random.rand(10, 3), index=list(string.ascii_letters[:10]))
+
+        axes = df.plot(subplots=True, layout=(2, 2))
+        self._check_axes_shape(axes, axes_num=3, layout=(2, 2))
+        assert axes.shape == (2, 2)
+
+        axes = df.plot(subplots=True, layout=(-1, 2))
+        self._check_axes_shape(axes, axes_num=3, layout=(2, 2))
+        assert axes.shape == (2, 2)
+
+        axes = df.plot(subplots=True, layout=(2, -1))
+        self._check_axes_shape(axes, axes_num=3, layout=(2, 2))
+        assert axes.shape == (2, 2)
+
+        axes = df.plot(subplots=True, layout=(1, 4))
+        self._check_axes_shape(axes, axes_num=3, layout=(1, 4))
+        assert axes.shape == (1, 4)
+
+        axes = df.plot(subplots=True, layout=(-1, 4))
+        self._check_axes_shape(axes, axes_num=3, layout=(1, 4))
+        assert axes.shape == (1, 4)
+
+        axes = df.plot(subplots=True, layout=(4, -1))
+        self._check_axes_shape(axes, axes_num=3, layout=(4, 1))
+        assert axes.shape == (4, 1)
+
+        msg = "Layout of 1x1 must be larger than required size 3"
+
+        with pytest.raises(ValueError, match=msg):
+            df.plot(subplots=True, layout=(1, 1))
+
+        msg = "At least one dimension of layout must be positive"
+        with pytest.raises(ValueError, match=msg):
+            df.plot(subplots=True, layout=(-1, -1))
+
+    @pytest.mark.parametrize(
+        "kwargs, expected_axes_num, expected_layout, expected_shape",
+        [
+            ({}, 1, (1, 1), (1,)),
+            ({"layout": (3, 3)}, 1, (3, 3), (3, 3)),
+        ],
+    )
+    def test_subplots_layout_single_column(
+        self, kwargs, expected_axes_num, expected_layout, expected_shape
+    ):
+
+        # GH 6667
+        df = DataFrame(np.random.rand(10, 1), index=list(string.ascii_letters[:10]))
+        axes = df.plot(subplots=True, **kwargs)
+        self._check_axes_shape(
+            axes,
+            axes_num=expected_axes_num,
+            layout=expected_layout,
+        )
+        assert axes.shape == expected_shape
+
+    def test_subplots_warnings(self):
+        # GH 9464
+        with tm.assert_produces_warning(None):
+            df = DataFrame(np.random.randn(100, 4))
+            df.plot(subplots=True, layout=(3, 2))
+
+            df = DataFrame(
+                np.random.randn(100, 4), index=date_range("1/1/2000", periods=100)
+            )
+            df.plot(subplots=True, layout=(3, 2))
+
+    def test_subplots_multiple_axes(self):
+        # GH 5353, 6970, GH 7069
+        fig, axes = self.plt.subplots(2, 3)
+        df = DataFrame(np.random.rand(10, 3), index=list(string.ascii_letters[:10]))
+
+        returned = df.plot(subplots=True, ax=axes[0], sharex=False, sharey=False)
+        self._check_axes_shape(returned, axes_num=3, layout=(1, 3))
+        assert returned.shape == (3,)
+        assert returned[0].figure is fig
+        # draw on second row
+        returned = df.plot(subplots=True, ax=axes[1], sharex=False, sharey=False)
+        self._check_axes_shape(returned, axes_num=3, layout=(1, 3))
+        assert returned.shape == (3,)
+        assert returned[0].figure is fig
+        self._check_axes_shape(axes, axes_num=6, layout=(2, 3))
+        tm.close()
+
+        msg = "The number of passed axes must be 3, the same as the output plot"
+
+        with pytest.raises(ValueError, match=msg):
+            fig, axes = self.plt.subplots(2, 3)
+            # pass different number of axes from required
+            df.plot(subplots=True, ax=axes)
+
+        # pass 2-dim axes and invalid layout
+        # invalid lauout should not affect to input and return value
+        # (show warning is tested in
+        # TestDataFrameGroupByPlots.test_grouped_box_multiple_axes
+        fig, axes = self.plt.subplots(2, 2)
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", UserWarning)
+            df = DataFrame(np.random.rand(10, 4), index=list(string.ascii_letters[:10]))
+
+            returned = df.plot(
+                subplots=True, ax=axes, layout=(2, 1), sharex=False, sharey=False
+            )
+            self._check_axes_shape(returned, axes_num=4, layout=(2, 2))
+            assert returned.shape == (4,)
+
+            returned = df.plot(
+                subplots=True, ax=axes, layout=(2, -1), sharex=False, sharey=False
+            )
+            self._check_axes_shape(returned, axes_num=4, layout=(2, 2))
+            assert returned.shape == (4,)
+
+            returned = df.plot(
+                subplots=True, ax=axes, layout=(-1, 2), sharex=False, sharey=False
+            )
+        self._check_axes_shape(returned, axes_num=4, layout=(2, 2))
+        assert returned.shape == (4,)
+
+        # single column
+        fig, axes = self.plt.subplots(1, 1)
+        df = DataFrame(np.random.rand(10, 1), index=list(string.ascii_letters[:10]))
+
+        axes = df.plot(subplots=True, ax=[axes], sharex=False, sharey=False)
+        self._check_axes_shape(axes, axes_num=1, layout=(1, 1))
+        assert axes.shape == (1,)
+
+    def test_subplots_ts_share_axes(self):
+        # GH 3964
+        fig, axes = self.plt.subplots(3, 3, sharex=True, sharey=True)
+        self.plt.subplots_adjust(left=0.05, right=0.95, hspace=0.3, wspace=0.3)
+        df = DataFrame(
+            np.random.randn(10, 9),
+            index=date_range(start="2014-07-01", freq="M", periods=10),
+        )
+        for i, ax in enumerate(axes.ravel()):
+            df[i].plot(ax=ax, fontsize=5)
+
+        # Rows other than bottom should not be visible
+        for ax in axes[0:-1].ravel():
+            self._check_visible(ax.get_xticklabels(), visible=False)
+
+        # Bottom row should be visible
+        for ax in axes[-1].ravel():
+            self._check_visible(ax.get_xticklabels(), visible=True)
+
+        # First column should be visible
+        for ax in axes[[0, 1, 2], [0]].ravel():
+            self._check_visible(ax.get_yticklabels(), visible=True)
+
+        # Other columns should not be visible
+        for ax in axes[[0, 1, 2], [1]].ravel():
+            self._check_visible(ax.get_yticklabels(), visible=False)
+        for ax in axes[[0, 1, 2], [2]].ravel():
+            self._check_visible(ax.get_yticklabels(), visible=False)
+
+    def test_subplots_sharex_axes_existing_axes(self):
+        # GH 9158
+        d = {"A": [1.0, 2.0, 3.0, 4.0], "B": [4.0, 3.0, 2.0, 1.0], "C": [5, 1, 3, 4]}
+        df = DataFrame(d, index=date_range("2014 10 11", "2014 10 14"))
+
+        axes = df[["A", "B"]].plot(subplots=True)
+        df["C"].plot(ax=axes[0], secondary_y=True)
+
+        self._check_visible(axes[0].get_xticklabels(), visible=False)
+        self._check_visible(axes[1].get_xticklabels(), visible=True)
+        for ax in axes.ravel():
+            self._check_visible(ax.get_yticklabels(), visible=True)
+
+    def test_subplots_dup_columns(self):
+        # GH 10962
+        df = DataFrame(np.random.rand(5, 5), columns=list("aaaaa"))
+        axes = df.plot(subplots=True)
+        for ax in axes:
+            self._check_legend_labels(ax, labels=["a"])
+            assert len(ax.lines) == 1
+        tm.close()
+
+        axes = df.plot(subplots=True, secondary_y="a")
+        for ax in axes:
+            # (right) is only attached when subplots=False
+            self._check_legend_labels(ax, labels=["a"])
+            assert len(ax.lines) == 1
+        tm.close()
+
+        ax = df.plot(secondary_y="a")
+        self._check_legend_labels(ax, labels=["a (right)"] * 5)
+        assert len(ax.lines) == 0
+        assert len(ax.right_ax.lines) == 5
+
+    def test_bar_log_no_subplots(self):
+        # GH3254, GH3298 matplotlib/matplotlib#1882, #1892
+        # regressions in 1.2.1
+        expected = np.array([0.1, 1.0, 10.0, 100])
+
+        # no subplots
+        df = DataFrame({"A": [3] * 5, "B": list(range(1, 6))}, index=range(5))
+        ax = df.plot.bar(grid=True, log=True)
+        tm.assert_numpy_array_equal(ax.yaxis.get_ticklocs(), expected)
+
+    def test_bar_log_subplots(self):
+        expected = np.array([0.1, 1.0, 10.0, 100.0, 1000.0, 1e4])
+
+        ax = DataFrame([Series([200, 300]), Series([300, 500])]).plot.bar(
+            log=True, subplots=True
+        )
+
+        tm.assert_numpy_array_equal(ax[0].yaxis.get_ticklocs(), expected)
+        tm.assert_numpy_array_equal(ax[1].yaxis.get_ticklocs(), expected)
+
+    def test_boxplot_subplots_return_type(self):
+        df = self.hist_df
+
+        # normal style: return_type=None
+        result = df.plot.box(subplots=True)
+        assert isinstance(result, Series)
+        self._check_box_return_type(
+            result, None, expected_keys=["height", "weight", "category"]
+        )
+
+        for t in ["dict", "axes", "both"]:
+            returned = df.plot.box(return_type=t, subplots=True)
+            self._check_box_return_type(
+                returned,
+                t,
+                expected_keys=["height", "weight", "category"],
+                check_ax_title=False,
+            )
+
+    def test_df_subplots_patterns_minorticks(self):
+        # GH 10657
+        import matplotlib.pyplot as plt
+
+        df = DataFrame(
+            np.random.randn(10, 2),
+            index=date_range("1/1/2000", periods=10),
+            columns=list("AB"),
+        )
+
+        # shared subplots
+        fig, axes = plt.subplots(2, 1, sharex=True)
+        axes = df.plot(subplots=True, ax=axes)
+        for ax in axes:
+            assert len(ax.lines) == 1
+            self._check_visible(ax.get_yticklabels(), visible=True)
+        # xaxis of 1st ax must be hidden
+        self._check_visible(axes[0].get_xticklabels(), visible=False)
+        self._check_visible(axes[0].get_xticklabels(minor=True), visible=False)
+        self._check_visible(axes[1].get_xticklabels(), visible=True)
+        self._check_visible(axes[1].get_xticklabels(minor=True), visible=True)
+        tm.close()
+
+        fig, axes = plt.subplots(2, 1)
+        with tm.assert_produces_warning(UserWarning):
+            axes = df.plot(subplots=True, ax=axes, sharex=True)
+        for ax in axes:
+            assert len(ax.lines) == 1
+            self._check_visible(ax.get_yticklabels(), visible=True)
+        # xaxis of 1st ax must be hidden
+        self._check_visible(axes[0].get_xticklabels(), visible=False)
+        self._check_visible(axes[0].get_xticklabels(minor=True), visible=False)
+        self._check_visible(axes[1].get_xticklabels(), visible=True)
+        self._check_visible(axes[1].get_xticklabels(minor=True), visible=True)
+        tm.close()
+
+        # not shared
+        fig, axes = plt.subplots(2, 1)
+        axes = df.plot(subplots=True, ax=axes)
+        for ax in axes:
+            assert len(ax.lines) == 1
+            self._check_visible(ax.get_yticklabels(), visible=True)
+            self._check_visible(ax.get_xticklabels(), visible=True)
+            self._check_visible(ax.get_xticklabels(minor=True), visible=True)
+        tm.close()
+
+    def test_subplots_sharex_false(self):
+        # test when sharex is set to False, two plots should have different
+        # labels, GH 25160
+        df = DataFrame(np.random.rand(10, 2))
+        df.iloc[5:, 1] = np.nan
+        df.iloc[:5, 0] = np.nan
+
+        figs, axs = self.plt.subplots(2, 1)
+        df.plot.line(ax=axs, subplots=True, sharex=False)
+
+        expected_ax1 = np.arange(4.5, 10, 0.5)
+        expected_ax2 = np.arange(-0.5, 5, 0.5)
+
+        tm.assert_numpy_array_equal(axs[0].get_xticks(), expected_ax1)
+        tm.assert_numpy_array_equal(axs[1].get_xticks(), expected_ax2)
+
+    def test_subplots_constrained_layout(self):
+        # GH 25261
+        idx = date_range(start="now", periods=10)
+        df = DataFrame(np.random.rand(10, 3), index=idx)
+        kwargs = {}
+        if hasattr(self.plt.Figure, "get_constrained_layout"):
+            kwargs["constrained_layout"] = True
+        fig, axes = self.plt.subplots(2, **kwargs)
+        with tm.assert_produces_warning(None):
+            df.plot(ax=axes[0])
+            with tm.ensure_clean(return_filelike=True) as path:
+                self.plt.savefig(path)
+
+    @pytest.mark.parametrize(
+        "index_name, old_label, new_label",
+        [
+            (None, "", "new"),
+            ("old", "old", "new"),
+            (None, "", ""),
+            (None, "", 1),
+            (None, "", [1, 2]),
+        ],
+    )
+    @pytest.mark.parametrize("kind", ["line", "area", "bar"])
+    def test_xlabel_ylabel_dataframe_subplots(
+        self, kind, index_name, old_label, new_label
+    ):
+        # GH 9093
+        df = DataFrame([[1, 2], [2, 5]], columns=["Type A", "Type B"])
+        df.index.name = index_name
+
+        # default is the ylabel is not shown and xlabel is index name
+        axes = df.plot(kind=kind, subplots=True)
+        assert all(ax.get_ylabel() == "" for ax in axes)
+        assert all(ax.get_xlabel() == old_label for ax in axes)
+
+        # old xlabel will be overridden and assigned ylabel will be used as ylabel
+        axes = df.plot(kind=kind, ylabel=new_label, xlabel=new_label, subplots=True)
+        assert all(ax.get_ylabel() == str(new_label) for ax in axes)
+        assert all(ax.get_xlabel() == str(new_label) for ax in axes)
+
+    @pytest.mark.parametrize(
+        "kwargs",
+        [
+            # stacked center
+            {"kind": "bar", "stacked": True},
+            {"kind": "bar", "stacked": True, "width": 0.9},
+            {"kind": "barh", "stacked": True},
+            {"kind": "barh", "stacked": True, "width": 0.9},
+            # center
+            {"kind": "bar", "stacked": False},
+            {"kind": "bar", "stacked": False, "width": 0.9},
+            {"kind": "barh", "stacked": False},
+            {"kind": "barh", "stacked": False, "width": 0.9},
+            # subplots center
+            {"kind": "bar", "subplots": True},
+            {"kind": "bar", "subplots": True, "width": 0.9},
+            {"kind": "barh", "subplots": True},
+            {"kind": "barh", "subplots": True, "width": 0.9},
+            # align edge
+            {"kind": "bar", "stacked": True, "align": "edge"},
+            {"kind": "bar", "stacked": True, "width": 0.9, "align": "edge"},
+            {"kind": "barh", "stacked": True, "align": "edge"},
+            {"kind": "barh", "stacked": True, "width": 0.9, "align": "edge"},
+            {"kind": "bar", "stacked": False, "align": "edge"},
+            {"kind": "bar", "stacked": False, "width": 0.9, "align": "edge"},
+            {"kind": "barh", "stacked": False, "align": "edge"},
+            {"kind": "barh", "stacked": False, "width": 0.9, "align": "edge"},
+            {"kind": "bar", "subplots": True, "align": "edge"},
+            {"kind": "bar", "subplots": True, "width": 0.9, "align": "edge"},
+            {"kind": "barh", "subplots": True, "align": "edge"},
+            {"kind": "barh", "subplots": True, "width": 0.9, "align": "edge"},
+        ],
+    )
+    def test_bar_align_multiple_columns(self, kwargs):
+        # GH2157
+        df = DataFrame({"A": [3] * 5, "B": list(range(5))}, index=range(5))
+        self._check_bar_alignment(df, **kwargs)
+
+    @pytest.mark.parametrize(
+        "kwargs",
+        [
+            {"kind": "bar", "stacked": False},
+            {"kind": "bar", "stacked": True},
+            {"kind": "barh", "stacked": False},
+            {"kind": "barh", "stacked": True},
+            {"kind": "bar", "subplots": True},
+            {"kind": "barh", "subplots": True},
+        ],
+    )
+    def test_bar_align_single_column(self, kwargs):
+        df = DataFrame(np.random.randn(5))
+        self._check_bar_alignment(df, **kwargs)
+
+    @pytest.mark.parametrize(
+        "kwargs",
+        [
+            {"kind": "bar", "stacked": False},
+            {"kind": "bar", "stacked": True},
+            {"kind": "barh", "stacked": False},
+            {"kind": "barh", "stacked": True},
+            {"kind": "bar", "subplots": True},
+            {"kind": "barh", "subplots": True},
+        ],
+    )
+    def test_bar_barwidth_position(self, kwargs):
+        df = DataFrame(np.random.randn(5, 5))
+        self._check_bar_alignment(df, width=0.9, position=0.2, **kwargs)
+
+    def test_bar_barwidth_position_int(self):
+        # GH 12979
+        df = DataFrame(np.random.randn(5, 5))
+
+        for w in [1, 1.0]:
+            ax = df.plot.bar(stacked=True, width=w)
+            ticks = ax.xaxis.get_ticklocs()
+            tm.assert_numpy_array_equal(ticks, np.array([0, 1, 2, 3, 4]))
+            assert ax.get_xlim() == (-0.75, 4.75)
+            # check left-edge of bars
+            assert ax.patches[0].get_x() == -0.5
+            assert ax.patches[-1].get_x() == 3.5
+
+        self._check_bar_alignment(df, kind="bar", stacked=True, width=1)
+        self._check_bar_alignment(df, kind="barh", stacked=False, width=1)
+        self._check_bar_alignment(df, kind="barh", stacked=True, width=1)
+        self._check_bar_alignment(df, kind="bar", subplots=True, width=1)
+        self._check_bar_alignment(df, kind="barh", subplots=True, width=1)
+
+    def _check_bar_alignment(
+        self,
+        df,
+        kind="bar",
+        stacked=False,
+        subplots=False,
+        align="center",
+        width=0.5,
+        position=0.5,
+    ):
+
+        axes = df.plot(
+            kind=kind,
+            stacked=stacked,
+            subplots=subplots,
+            align=align,
+            width=width,
+            position=position,
+            grid=True,
+        )
+
+        axes = self._flatten_visible(axes)
+
+        for ax in axes:
+            if kind == "bar":
+                axis = ax.xaxis
+                ax_min, ax_max = ax.get_xlim()
+                min_edge = min(p.get_x() for p in ax.patches)
+                max_edge = max(p.get_x() + p.get_width() for p in ax.patches)
+            elif kind == "barh":
+                axis = ax.yaxis
+                ax_min, ax_max = ax.get_ylim()
+                min_edge = min(p.get_y() for p in ax.patches)
+                max_edge = max(p.get_y() + p.get_height() for p in ax.patches)
+            else:
+                raise ValueError
+
+            # GH 7498
+            # compare margins between lim and bar edges
+            tm.assert_almost_equal(ax_min, min_edge - 0.25)
+            tm.assert_almost_equal(ax_max, max_edge + 0.25)
+
+            p = ax.patches[0]
+            if kind == "bar" and (stacked is True or subplots is True):
+                edge = p.get_x()
+                center = edge + p.get_width() * position
+            elif kind == "bar" and stacked is False:
+                center = p.get_x() + p.get_width() * len(df.columns) * position
+                edge = p.get_x()
+            elif kind == "barh" and (stacked is True or subplots is True):
+                center = p.get_y() + p.get_height() * position
+                edge = p.get_y()
+            elif kind == "barh" and stacked is False:
+                center = p.get_y() + p.get_height() * len(df.columns) * position
+                edge = p.get_y()
+            else:
+                raise ValueError
+
+            # Check the ticks locates on integer
+            assert (axis.get_ticklocs() == np.arange(len(df))).all()
+
+            if align == "center":
+                # Check whether the bar locates on center
+                tm.assert_almost_equal(axis.get_ticklocs()[0], center)
+            elif align == "edge":
+                # Check whether the bar's edge starts from the tick
+                tm.assert_almost_equal(axis.get_ticklocs()[0], edge)
+            else:
+                raise ValueError
+
+        return axes

.venv/Lib/site-packages/pandas/tests/plotting/frame/test_hist_box_by.py

@@ -0,0 +1,389 @@
+import re
+
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+from pandas import DataFrame
+import pandas._testing as tm
+from pandas.tests.plotting.common import (
+    TestPlotBase,
+    _check_plot_works,
+)
+
+
+def _create_hist_box_with_by_df():
+    np.random.seed(0)
+    df = DataFrame(np.random.randn(30, 2), columns=["A", "B"])
+    df["C"] = np.random.choice(["a", "b", "c"], 30)
+    df["D"] = np.random.choice(["a", "b", "c"], 30)
+    return df
+
+
+@td.skip_if_no_mpl
+class TestHistWithBy(TestPlotBase):
+    def setup_method(self, method):
+        TestPlotBase.setup_method(self, method)
+        import matplotlib as mpl
+
+        mpl.rcdefaults()
+        self.hist_df = _create_hist_box_with_by_df()
+
+    @pytest.mark.parametrize(
+        "by, column, titles, legends",
+        [
+            ("C", "A", ["a", "b", "c"], [["A"]] * 3),
+            ("C", ["A", "B"], ["a", "b", "c"], [["A", "B"]] * 3),
+            ("C", None, ["a", "b", "c"], [["A", "B"]] * 3),
+            (
+                ["C", "D"],
+                "A",
+                [
+                    "(a, a)",
+                    "(a, b)",
+                    "(a, c)",
+                    "(b, a)",
+                    "(b, b)",
+                    "(b, c)",
+                    "(c, a)",
+                    "(c, b)",
+                    "(c, c)",
+                ],
+                [["A"]] * 9,
+            ),
+            (
+                ["C", "D"],
+                ["A", "B"],
+                [
+                    "(a, a)",
+                    "(a, b)",
+                    "(a, c)",
+                    "(b, a)",
+                    "(b, b)",
+                    "(b, c)",
+                    "(c, a)",
+                    "(c, b)",
+                    "(c, c)",
+                ],
+                [["A", "B"]] * 9,
+            ),
+            (
+                ["C", "D"],
+                None,
+                [
+                    "(a, a)",
+                    "(a, b)",
+                    "(a, c)",
+                    "(b, a)",
+                    "(b, b)",
+                    "(b, c)",
+                    "(c, a)",
+                    "(c, b)",
+                    "(c, c)",
+                ],
+                [["A", "B"]] * 9,
+            ),
+        ],
+    )
+    def test_hist_plot_by_argument(self, by, column, titles, legends):
+        # GH 15079
+        axes = _check_plot_works(self.hist_df.plot.hist, column=column, by=by)
+        result_titles = [ax.get_title() for ax in axes]
+        result_legends = [
+            [legend.get_text() for legend in ax.get_legend().texts] for ax in axes
+        ]
+
+        assert result_legends == legends
+        assert result_titles == titles
+
+    @pytest.mark.parametrize(
+        "by, column, titles, legends",
+        [
+            (0, "A", ["a", "b", "c"], [["A"]] * 3),
+            (0, None, ["a", "b", "c"], [["A", "B"]] * 3),
+            (
+                [0, "D"],
+                "A",
+                [
+                    "(a, a)",
+                    "(a, b)",
+                    "(a, c)",
+                    "(b, a)",
+                    "(b, b)",
+                    "(b, c)",
+                    "(c, a)",
+                    "(c, b)",
+                    "(c, c)",
+                ],
+                [["A"]] * 9,
+            ),
+        ],
+    )
+    def test_hist_plot_by_0(self, by, column, titles, legends):
+        # GH 15079
+        df = self.hist_df.copy()
+        df = df.rename(columns={"C": 0})
+
+        axes = _check_plot_works(df.plot.hist, column=column, by=by)
+        result_titles = [ax.get_title() for ax in axes]
+        result_legends = [
+            [legend.get_text() for legend in ax.get_legend().texts] for ax in axes
+        ]
+
+        assert result_legends == legends
+        assert result_titles == titles
+
+    @pytest.mark.parametrize(
+        "by, column",
+        [
+            ([], ["A"]),
+            ([], ["A", "B"]),
+            ((), None),
+            ((), ["A", "B"]),
+        ],
+    )
+    def test_hist_plot_empty_list_string_tuple_by(self, by, column):
+        # GH 15079
+        msg = "No group keys passed"
+        with pytest.raises(ValueError, match=msg):
+            _check_plot_works(self.hist_df.plot.hist, column=column, by=by)
+
+    @pytest.mark.slow
+    @pytest.mark.parametrize(
+        "by, column, layout, axes_num",
+        [
+            (["C"], "A", (2, 2), 3),
+            ("C", "A", (2, 2), 3),
+            (["C"], ["A"], (1, 3), 3),
+            ("C", None, (3, 1), 3),
+            ("C", ["A", "B"], (3, 1), 3),
+            (["C", "D"], "A", (9, 1), 9),
+            (["C", "D"], "A", (3, 3), 9),
+            (["C", "D"], ["A"], (5, 2), 9),
+            (["C", "D"], ["A", "B"], (9, 1), 9),
+            (["C", "D"], None, (9, 1), 9),
+            (["C", "D"], ["A", "B"], (5, 2), 9),
+        ],
+    )
+    def test_hist_plot_layout_with_by(self, by, column, layout, axes_num):
+        # GH 15079
+        # _check_plot_works adds an ax so catch warning. see GH #13188
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(
+                self.hist_df.plot.hist, column=column, by=by, layout=layout
+            )
+        self._check_axes_shape(axes, axes_num=axes_num, layout=layout)
+
+    @pytest.mark.parametrize(
+        "msg, by, layout",
+        [
+            ("larger than required size", ["C", "D"], (1, 1)),
+            (re.escape("Layout must be a tuple of (rows, columns)"), "C", (1,)),
+            ("At least one dimension of layout must be positive", "C", (-1, -1)),
+        ],
+    )
+    def test_hist_plot_invalid_layout_with_by_raises(self, msg, by, layout):
+        # GH 15079, test if error is raised when invalid layout is given
+
+        with pytest.raises(ValueError, match=msg):
+            self.hist_df.plot.hist(column=["A", "B"], by=by, layout=layout)
+
+    @pytest.mark.slow
+    def test_axis_share_x_with_by(self):
+        # GH 15079
+        ax1, ax2, ax3 = self.hist_df.plot.hist(column="A", by="C", sharex=True)
+
+        # share x
+        assert self.get_x_axis(ax1).joined(ax1, ax2)
+        assert self.get_x_axis(ax2).joined(ax1, ax2)
+        assert self.get_x_axis(ax3).joined(ax1, ax3)
+        assert self.get_x_axis(ax3).joined(ax2, ax3)
+
+        # don't share y
+        assert not self.get_y_axis(ax1).joined(ax1, ax2)
+        assert not self.get_y_axis(ax2).joined(ax1, ax2)
+        assert not self.get_y_axis(ax3).joined(ax1, ax3)
+        assert not self.get_y_axis(ax3).joined(ax2, ax3)
+
+    @pytest.mark.slow
+    def test_axis_share_y_with_by(self):
+        # GH 15079
+        ax1, ax2, ax3 = self.hist_df.plot.hist(column="A", by="C", sharey=True)
+
+        # share y
+        assert self.get_y_axis(ax1).joined(ax1, ax2)
+        assert self.get_y_axis(ax2).joined(ax1, ax2)
+        assert self.get_y_axis(ax3).joined(ax1, ax3)
+        assert self.get_y_axis(ax3).joined(ax2, ax3)
+
+        # don't share x
+        assert not self.get_x_axis(ax1).joined(ax1, ax2)
+        assert not self.get_x_axis(ax2).joined(ax1, ax2)
+        assert not self.get_x_axis(ax3).joined(ax1, ax3)
+        assert not self.get_x_axis(ax3).joined(ax2, ax3)
+
+    @pytest.mark.parametrize("figsize", [(12, 8), (20, 10)])
+    def test_figure_shape_hist_with_by(self, figsize):
+        # GH 15079
+        axes = self.hist_df.plot.hist(column="A", by="C", figsize=figsize)
+        self._check_axes_shape(axes, axes_num=3, figsize=figsize)
+
+
+@td.skip_if_no_mpl
+class TestBoxWithBy(TestPlotBase):
+    def setup_method(self, method):
+        TestPlotBase.setup_method(self, method)
+        import matplotlib as mpl
+
+        mpl.rcdefaults()
+        self.box_df = _create_hist_box_with_by_df()
+
+    @pytest.mark.parametrize(
+        "by, column, titles, xticklabels",
+        [
+            ("C", "A", ["A"], [["a", "b", "c"]]),
+            (
+                ["C", "D"],
+                "A",
+                ["A"],
+                [
+                    [
+                        "(a, a)",
+                        "(a, b)",
+                        "(a, c)",
+                        "(b, a)",
+                        "(b, b)",
+                        "(b, c)",
+                        "(c, a)",
+                        "(c, b)",
+                        "(c, c)",
+                    ]
+                ],
+            ),
+            ("C", ["A", "B"], ["A", "B"], [["a", "b", "c"]] * 2),
+            (
+                ["C", "D"],
+                ["A", "B"],
+                ["A", "B"],
+                [
+                    [
+                        "(a, a)",
+                        "(a, b)",
+                        "(a, c)",
+                        "(b, a)",
+                        "(b, b)",
+                        "(b, c)",
+                        "(c, a)",
+                        "(c, b)",
+                        "(c, c)",
+                    ]
+                ]
+                * 2,
+            ),
+            (["C"], None, ["A", "B"], [["a", "b", "c"]] * 2),
+        ],
+    )
+    def test_box_plot_by_argument(self, by, column, titles, xticklabels):
+        # GH 15079
+        axes = _check_plot_works(self.box_df.plot.box, column=column, by=by)
+        result_titles = [ax.get_title() for ax in axes]
+        result_xticklabels = [
+            [label.get_text() for label in ax.get_xticklabels()] for ax in axes
+        ]
+
+        assert result_xticklabels == xticklabels
+        assert result_titles == titles
+
+    @pytest.mark.parametrize(
+        "by, column, titles, xticklabels",
+        [
+            (0, "A", ["A"], [["a", "b", "c"]]),
+            (
+                [0, "D"],
+                "A",
+                ["A"],
+                [
+                    [
+                        "(a, a)",
+                        "(a, b)",
+                        "(a, c)",
+                        "(b, a)",
+                        "(b, b)",
+                        "(b, c)",
+                        "(c, a)",
+                        "(c, b)",
+                        "(c, c)",
+                    ]
+                ],
+            ),
+            (0, None, ["A", "B"], [["a", "b", "c"]] * 2),
+        ],
+    )
+    def test_box_plot_by_0(self, by, column, titles, xticklabels):
+        # GH 15079
+        df = self.box_df.copy()
+        df = df.rename(columns={"C": 0})
+
+        axes = _check_plot_works(df.plot.box, column=column, by=by)
+        result_titles = [ax.get_title() for ax in axes]
+        result_xticklabels = [
+            [label.get_text() for label in ax.get_xticklabels()] for ax in axes
+        ]
+
+        assert result_xticklabels == xticklabels
+        assert result_titles == titles
+
+    @pytest.mark.parametrize(
+        "by, column",
+        [
+            ([], ["A"]),
+            ((), "A"),
+            ([], None),
+            ((), ["A", "B"]),
+        ],
+    )
+    def test_box_plot_with_none_empty_list_by(self, by, column):
+        # GH 15079
+        msg = "No group keys passed"
+        with pytest.raises(ValueError, match=msg):
+            _check_plot_works(self.box_df.plot.box, column=column, by=by)
+
+    @pytest.mark.slow
+    @pytest.mark.parametrize(
+        "by, column, layout, axes_num",
+        [
+            (["C"], "A", (1, 1), 1),
+            ("C", "A", (1, 1), 1),
+            ("C", None, (2, 1), 2),
+            ("C", ["A", "B"], (1, 2), 2),
+            (["C", "D"], "A", (1, 1), 1),
+            (["C", "D"], None, (1, 2), 2),
+        ],
+    )
+    def test_box_plot_layout_with_by(self, by, column, layout, axes_num):
+        # GH 15079
+        axes = _check_plot_works(
+            self.box_df.plot.box, column=column, by=by, layout=layout
+        )
+        self._check_axes_shape(axes, axes_num=axes_num, layout=layout)
+
+    @pytest.mark.parametrize(
+        "msg, by, layout",
+        [
+            ("larger than required size", ["C", "D"], (1, 1)),
+            (re.escape("Layout must be a tuple of (rows, columns)"), "C", (1,)),
+            ("At least one dimension of layout must be positive", "C", (-1, -1)),
+        ],
+    )
+    def test_box_plot_invalid_layout_with_by_raises(self, msg, by, layout):
+        # GH 15079, test if error is raised when invalid layout is given
+
+        with pytest.raises(ValueError, match=msg):
+            self.box_df.plot.box(column=["A", "B"], by=by, layout=layout)
+
+    @pytest.mark.parametrize("figsize", [(12, 8), (20, 10)])
+    def test_figure_shape_hist_with_by(self, figsize):
+        # GH 15079
+        axes = self.box_df.plot.box(column="A", by="C", figsize=figsize)
+        self._check_axes_shape(axes, axes_num=1, figsize=figsize)

.venv/Lib/site-packages/pandas/tests/plotting/test_backend.py

@@ -0,0 +1,111 @@
+import sys
+import types
+
+import pkg_resources
+import pytest
+
+import pandas.util._test_decorators as td
+
+import pandas
+
+dummy_backend = types.ModuleType("pandas_dummy_backend")
+setattr(dummy_backend, "plot", lambda *args, **kwargs: "used_dummy")
+
+
+pytestmark = pytest.mark.slow
+
+
+@pytest.fixture
+def restore_backend():
+    """Restore the plotting backend to matplotlib"""
+    pandas.set_option("plotting.backend", "matplotlib")
+    yield
+    pandas.set_option("plotting.backend", "matplotlib")
+
+
+def test_backend_is_not_module():
+    msg = "Could not find plotting backend 'not_an_existing_module'."
+    with pytest.raises(ValueError, match=msg):
+        pandas.set_option("plotting.backend", "not_an_existing_module")
+
+    assert pandas.options.plotting.backend == "matplotlib"
+
+
+def test_backend_is_correct(monkeypatch, restore_backend):
+    monkeypatch.setitem(sys.modules, "pandas_dummy_backend", dummy_backend)
+
+    pandas.set_option("plotting.backend", "pandas_dummy_backend")
+    assert pandas.get_option("plotting.backend") == "pandas_dummy_backend"
+    assert (
+        pandas.plotting._core._get_plot_backend("pandas_dummy_backend") is dummy_backend
+    )
+
+
+def test_backend_can_be_set_in_plot_call(monkeypatch, restore_backend):
+    monkeypatch.setitem(sys.modules, "pandas_dummy_backend", dummy_backend)
+    df = pandas.DataFrame([1, 2, 3])
+
+    assert pandas.get_option("plotting.backend") == "matplotlib"
+    assert df.plot(backend="pandas_dummy_backend") == "used_dummy"
+
+
+@td.skip_if_no_mpl
+def test_register_entrypoint(restore_backend):
+
+    dist = pkg_resources.get_distribution("pandas")
+    if dist.module_path not in pandas.__file__:
+        # We are running from a non-installed pandas, and this test is invalid
+        pytest.skip("Testing a non-installed pandas")
+
+    mod = types.ModuleType("my_backend")
+    mod.plot = lambda *args, **kwargs: 1
+
+    backends = pkg_resources.get_entry_map("pandas")
+    my_entrypoint = pkg_resources.EntryPoint(
+        "pandas_plotting_backend", mod.__name__, dist=dist
+    )
+    backends["pandas_plotting_backends"]["my_backend"] = my_entrypoint
+    # TODO: the docs recommend importlib.util.module_from_spec. But this works for now.
+    sys.modules["my_backend"] = mod
+
+    result = pandas.plotting._core._get_plot_backend("my_backend")
+    assert result is mod
+
+    # TODO(GH#27517): https://github.com/pandas-dev/pandas/issues/27517
+    # Remove the td.skip_if_no_mpl
+    with pandas.option_context("plotting.backend", "my_backend"):
+        result = pandas.plotting._core._get_plot_backend()
+
+    assert result is mod
+
+
+def test_setting_backend_without_plot_raises():
+    # GH-28163
+    module = types.ModuleType("pandas_plot_backend")
+    sys.modules["pandas_plot_backend"] = module
+
+    assert pandas.options.plotting.backend == "matplotlib"
+    with pytest.raises(
+        ValueError, match="Could not find plotting backend 'pandas_plot_backend'."
+    ):
+        pandas.set_option("plotting.backend", "pandas_plot_backend")
+
+    assert pandas.options.plotting.backend == "matplotlib"
+
+
+@td.skip_if_mpl
+def test_no_matplotlib_ok():
+    msg = (
+        'matplotlib is required for plotting when the default backend "matplotlib" is '
+        "selected."
+    )
+    with pytest.raises(ImportError, match=msg):
+        pandas.plotting._core._get_plot_backend("matplotlib")
+
+
+def test_extra_kinds_ok(monkeypatch, restore_backend):
+    # https://github.com/pandas-dev/pandas/pull/28647
+    monkeypatch.setitem(sys.modules, "pandas_dummy_backend", dummy_backend)
+    pandas.set_option("plotting.backend", "pandas_dummy_backend")
+    df = pandas.DataFrame({"A": [1, 2, 3]})
+    df.plot(kind="not a real kind")

.venv/Lib/site-packages/pandas/tests/plotting/test_boxplot_method.py

@@ -0,0 +1,568 @@
+""" Test cases for .boxplot method """
+
+import itertools
+import string
+
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+from pandas import (
+    DataFrame,
+    MultiIndex,
+    Series,
+    date_range,
+    timedelta_range,
+)
+import pandas._testing as tm
+from pandas.tests.plotting.common import (
+    TestPlotBase,
+    _check_plot_works,
+)
+
+import pandas.plotting as plotting
+
+pytestmark = pytest.mark.slow
+
+
+@td.skip_if_no_mpl
+class TestDataFramePlots(TestPlotBase):
+    def test_boxplot_legacy1(self):
+        df = DataFrame(
+            np.random.randn(6, 4),
+            index=list(string.ascii_letters[:6]),
+            columns=["one", "two", "three", "four"],
+        )
+        df["indic"] = ["foo", "bar"] * 3
+        df["indic2"] = ["foo", "bar", "foo"] * 2
+
+        _check_plot_works(df.boxplot, return_type="dict")
+        _check_plot_works(df.boxplot, column=["one", "two"], return_type="dict")
+        # _check_plot_works adds an ax so catch warning. see GH #13188
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(df.boxplot, column=["one", "two"], by="indic")
+        _check_plot_works(df.boxplot, column="one", by=["indic", "indic2"])
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(df.boxplot, by="indic")
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(df.boxplot, by=["indic", "indic2"])
+        _check_plot_works(plotting._core.boxplot, data=df["one"], return_type="dict")
+        _check_plot_works(df.boxplot, notch=1, return_type="dict")
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(df.boxplot, by="indic", notch=1)
+
+    def test_boxplot_legacy2(self):
+        df = DataFrame(np.random.rand(10, 2), columns=["Col1", "Col2"])
+        df["X"] = Series(["A", "A", "A", "A", "A", "B", "B", "B", "B", "B"])
+        df["Y"] = Series(["A"] * 10)
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(df.boxplot, by="X")
+
+        # When ax is supplied and required number of axes is 1,
+        # passed ax should be used:
+        fig, ax = self.plt.subplots()
+        axes = df.boxplot("Col1", by="X", ax=ax)
+        ax_axes = ax.axes
+        assert ax_axes is axes
+
+        fig, ax = self.plt.subplots()
+        axes = df.groupby("Y").boxplot(ax=ax, return_type="axes")
+        ax_axes = ax.axes
+        assert ax_axes is axes["A"]
+
+        # Multiple columns with an ax argument should use same figure
+        fig, ax = self.plt.subplots()
+        with tm.assert_produces_warning(UserWarning):
+            axes = df.boxplot(
+                column=["Col1", "Col2"], by="X", ax=ax, return_type="axes"
+            )
+        assert axes["Col1"].get_figure() is fig
+
+        # When by is None, check that all relevant lines are present in the
+        # dict
+        fig, ax = self.plt.subplots()
+        d = df.boxplot(ax=ax, return_type="dict")
+        lines = list(itertools.chain.from_iterable(d.values()))
+        assert len(ax.get_lines()) == len(lines)
+
+    def test_boxplot_return_type_none(self):
+        # GH 12216; return_type=None & by=None -> axes
+        result = self.hist_df.boxplot()
+        assert isinstance(result, self.plt.Axes)
+
+    def test_boxplot_return_type_legacy(self):
+        # API change in https://github.com/pandas-dev/pandas/pull/7096
+
+        df = DataFrame(
+            np.random.randn(6, 4),
+            index=list(string.ascii_letters[:6]),
+            columns=["one", "two", "three", "four"],
+        )
+        msg = "return_type must be {'axes', 'dict', 'both'}"
+        with pytest.raises(ValueError, match=msg):
+            df.boxplot(return_type="NOT_A_TYPE")
+
+        result = df.boxplot()
+        self._check_box_return_type(result, "axes")
+
+        with tm.assert_produces_warning(False):
+            result = df.boxplot(return_type="dict")
+        self._check_box_return_type(result, "dict")
+
+        with tm.assert_produces_warning(False):
+            result = df.boxplot(return_type="axes")
+        self._check_box_return_type(result, "axes")
+
+        with tm.assert_produces_warning(False):
+            result = df.boxplot(return_type="both")
+        self._check_box_return_type(result, "both")
+
+    def test_boxplot_axis_limits(self):
+        def _check_ax_limits(col, ax):
+            y_min, y_max = ax.get_ylim()
+            assert y_min <= col.min()
+            assert y_max >= col.max()
+
+        df = self.hist_df.copy()
+        df["age"] = np.random.randint(1, 20, df.shape[0])
+        # One full row
+        height_ax, weight_ax = df.boxplot(["height", "weight"], by="category")
+        _check_ax_limits(df["height"], height_ax)
+        _check_ax_limits(df["weight"], weight_ax)
+        assert weight_ax._sharey == height_ax
+
+        # Two rows, one partial
+        p = df.boxplot(["height", "weight", "age"], by="category")
+        height_ax, weight_ax, age_ax = p[0, 0], p[0, 1], p[1, 0]
+        dummy_ax = p[1, 1]
+
+        _check_ax_limits(df["height"], height_ax)
+        _check_ax_limits(df["weight"], weight_ax)
+        _check_ax_limits(df["age"], age_ax)
+        assert weight_ax._sharey == height_ax
+        assert age_ax._sharey == height_ax
+        assert dummy_ax._sharey is None
+
+    def test_boxplot_empty_column(self):
+        df = DataFrame(np.random.randn(20, 4))
+        df.loc[:, 0] = np.nan
+        _check_plot_works(df.boxplot, return_type="axes")
+
+    def test_figsize(self):
+        df = DataFrame(np.random.rand(10, 5), columns=["A", "B", "C", "D", "E"])
+        result = df.boxplot(return_type="axes", figsize=(12, 8))
+        assert result.figure.bbox_inches.width == 12
+        assert result.figure.bbox_inches.height == 8
+
+    def test_fontsize(self):
+        df = DataFrame({"a": [1, 2, 3, 4, 5, 6]})
+        self._check_ticks_props(
+            df.boxplot("a", fontsize=16), xlabelsize=16, ylabelsize=16
+        )
+
+    def test_boxplot_numeric_data(self):
+        # GH 22799
+        df = DataFrame(
+            {
+                "a": date_range("2012-01-01", periods=100),
+                "b": np.random.randn(100),
+                "c": np.random.randn(100) + 2,
+                "d": date_range("2012-01-01", periods=100).astype(str),
+                "e": date_range("2012-01-01", periods=100, tz="UTC"),
+                "f": timedelta_range("1 days", periods=100),
+            }
+        )
+        ax = df.plot(kind="box")
+        assert [x.get_text() for x in ax.get_xticklabels()] == ["b", "c"]
+
+    @pytest.mark.parametrize(
+        "colors_kwd, expected",
+        [
+            (
+                {"boxes": "r", "whiskers": "b", "medians": "g", "caps": "c"},
+                {"boxes": "r", "whiskers": "b", "medians": "g", "caps": "c"},
+            ),
+            ({"boxes": "r"}, {"boxes": "r"}),
+            ("r", {"boxes": "r", "whiskers": "r", "medians": "r", "caps": "r"}),
+        ],
+    )
+    def test_color_kwd(self, colors_kwd, expected):
+        # GH: 26214
+        df = DataFrame(np.random.rand(10, 2))
+        result = df.boxplot(color=colors_kwd, return_type="dict")
+        for k, v in expected.items():
+            assert result[k][0].get_color() == v
+
+    @pytest.mark.parametrize(
+        "scheme,expected",
+        [
+            (
+                "dark_background",
+                {
+                    "boxes": "#8dd3c7",
+                    "whiskers": "#8dd3c7",
+                    "medians": "#bfbbd9",
+                    "caps": "#8dd3c7",
+                },
+            ),
+            (
+                "default",
+                {
+                    "boxes": "#1f77b4",
+                    "whiskers": "#1f77b4",
+                    "medians": "#2ca02c",
+                    "caps": "#1f77b4",
+                },
+            ),
+        ],
+    )
+    def test_colors_in_theme(self, scheme, expected):
+        # GH: 40769
+        df = DataFrame(np.random.rand(10, 2))
+        import matplotlib.pyplot as plt
+
+        plt.style.use(scheme)
+        result = df.plot.box(return_type="dict")
+        for k, v in expected.items():
+            assert result[k][0].get_color() == v
+
+    @pytest.mark.parametrize(
+        "dict_colors, msg",
+        [({"boxes": "r", "invalid_key": "r"}, "invalid key 'invalid_key'")],
+    )
+    def test_color_kwd_errors(self, dict_colors, msg):
+        # GH: 26214
+        df = DataFrame(np.random.rand(10, 2))
+        with pytest.raises(ValueError, match=msg):
+            df.boxplot(color=dict_colors, return_type="dict")
+
+    @pytest.mark.parametrize(
+        "props, expected",
+        [
+            ("boxprops", "boxes"),
+            ("whiskerprops", "whiskers"),
+            ("capprops", "caps"),
+            ("medianprops", "medians"),
+        ],
+    )
+    def test_specified_props_kwd(self, props, expected):
+        # GH 30346
+        df = DataFrame({k: np.random.random(100) for k in "ABC"})
+        kwd = {props: {"color": "C1"}}
+        result = df.boxplot(return_type="dict", **kwd)
+
+        assert result[expected][0].get_color() == "C1"
+
+
+@td.skip_if_no_mpl
+class TestDataFrameGroupByPlots(TestPlotBase):
+    def test_boxplot_legacy1(self):
+        grouped = self.hist_df.groupby(by="gender")
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(grouped.boxplot, return_type="axes")
+        self._check_axes_shape(list(axes.values), axes_num=2, layout=(1, 2))
+        axes = _check_plot_works(grouped.boxplot, subplots=False, return_type="axes")
+        self._check_axes_shape(axes, axes_num=1, layout=(1, 1))
+
+    def test_boxplot_legacy2(self):
+        tuples = zip(string.ascii_letters[:10], range(10))
+        df = DataFrame(np.random.rand(10, 3), index=MultiIndex.from_tuples(tuples))
+        grouped = df.groupby(level=1)
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(grouped.boxplot, return_type="axes")
+        self._check_axes_shape(list(axes.values), axes_num=10, layout=(4, 3))
+
+        axes = _check_plot_works(grouped.boxplot, subplots=False, return_type="axes")
+        self._check_axes_shape(axes, axes_num=1, layout=(1, 1))
+
+    def test_boxplot_legacy3(self):
+        tuples = zip(string.ascii_letters[:10], range(10))
+        df = DataFrame(np.random.rand(10, 3), index=MultiIndex.from_tuples(tuples))
+        grouped = df.unstack(level=1).groupby(level=0, axis=1)
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(grouped.boxplot, return_type="axes")
+        self._check_axes_shape(list(axes.values), axes_num=3, layout=(2, 2))
+        axes = _check_plot_works(grouped.boxplot, subplots=False, return_type="axes")
+        self._check_axes_shape(axes, axes_num=1, layout=(1, 1))
+
+    def test_grouped_plot_fignums(self):
+        n = 10
+        weight = Series(np.random.normal(166, 20, size=n))
+        height = Series(np.random.normal(60, 10, size=n))
+        with tm.RNGContext(42):
+            gender = np.random.choice(["male", "female"], size=n)
+        df = DataFrame({"height": height, "weight": weight, "gender": gender})
+        gb = df.groupby("gender")
+
+        res = gb.plot()
+        assert len(self.plt.get_fignums()) == 2
+        assert len(res) == 2
+        tm.close()
+
+        res = gb.boxplot(return_type="axes")
+        assert len(self.plt.get_fignums()) == 1
+        assert len(res) == 2
+        tm.close()
+
+        # now works with GH 5610 as gender is excluded
+        res = df.groupby("gender").hist()
+        tm.close()
+
+    def test_grouped_box_return_type(self):
+        df = self.hist_df
+
+        # old style: return_type=None
+        result = df.boxplot(by="gender")
+        assert isinstance(result, np.ndarray)
+        self._check_box_return_type(
+            result, None, expected_keys=["height", "weight", "category"]
+        )
+
+        # now for groupby
+        result = df.groupby("gender").boxplot(return_type="dict")
+        self._check_box_return_type(result, "dict", expected_keys=["Male", "Female"])
+
+        columns2 = "X B C D A G Y N Q O".split()
+        df2 = DataFrame(np.random.randn(50, 10), columns=columns2)
+        categories2 = "A B C D E F G H I J".split()
+        df2["category"] = categories2 * 5
+
+        for t in ["dict", "axes", "both"]:
+            returned = df.groupby("classroom").boxplot(return_type=t)
+            self._check_box_return_type(returned, t, expected_keys=["A", "B", "C"])
+
+            returned = df.boxplot(by="classroom", return_type=t)
+            self._check_box_return_type(
+                returned, t, expected_keys=["height", "weight", "category"]
+            )
+
+            returned = df2.groupby("category").boxplot(return_type=t)
+            self._check_box_return_type(returned, t, expected_keys=categories2)
+
+            returned = df2.boxplot(by="category", return_type=t)
+            self._check_box_return_type(returned, t, expected_keys=columns2)
+
+    def test_grouped_box_layout(self):
+        df = self.hist_df
+
+        msg = "Layout of 1x1 must be larger than required size 2"
+        with pytest.raises(ValueError, match=msg):
+            df.boxplot(column=["weight", "height"], by=df.gender, layout=(1, 1))
+
+        msg = "The 'layout' keyword is not supported when 'by' is None"
+        with pytest.raises(ValueError, match=msg):
+            df.boxplot(
+                column=["height", "weight", "category"],
+                layout=(2, 1),
+                return_type="dict",
+            )
+
+        msg = "At least one dimension of layout must be positive"
+        with pytest.raises(ValueError, match=msg):
+            df.boxplot(column=["weight", "height"], by=df.gender, layout=(-1, -1))
+
+        # _check_plot_works adds an ax so catch warning. see GH #13188
+        with tm.assert_produces_warning(UserWarning):
+            box = _check_plot_works(
+                df.groupby("gender").boxplot, column="height", return_type="dict"
+            )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=2, layout=(1, 2))
+
+        with tm.assert_produces_warning(UserWarning):
+            box = _check_plot_works(
+                df.groupby("category").boxplot, column="height", return_type="dict"
+            )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=4, layout=(2, 2))
+
+        # GH 6769
+        with tm.assert_produces_warning(UserWarning):
+            box = _check_plot_works(
+                df.groupby("classroom").boxplot, column="height", return_type="dict"
+            )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=3, layout=(2, 2))
+
+        # GH 5897
+        axes = df.boxplot(
+            column=["height", "weight", "category"], by="gender", return_type="axes"
+        )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=3, layout=(2, 2))
+        for ax in [axes["height"]]:
+            self._check_visible(ax.get_xticklabels(), visible=False)
+            self._check_visible([ax.xaxis.get_label()], visible=False)
+        for ax in [axes["weight"], axes["category"]]:
+            self._check_visible(ax.get_xticklabels())
+            self._check_visible([ax.xaxis.get_label()])
+
+        box = df.groupby("classroom").boxplot(
+            column=["height", "weight", "category"], return_type="dict"
+        )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=3, layout=(2, 2))
+
+        with tm.assert_produces_warning(UserWarning):
+            box = _check_plot_works(
+                df.groupby("category").boxplot,
+                column="height",
+                layout=(3, 2),
+                return_type="dict",
+            )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=4, layout=(3, 2))
+        with tm.assert_produces_warning(UserWarning):
+            box = _check_plot_works(
+                df.groupby("category").boxplot,
+                column="height",
+                layout=(3, -1),
+                return_type="dict",
+            )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=4, layout=(3, 2))
+
+        box = df.boxplot(
+            column=["height", "weight", "category"], by="gender", layout=(4, 1)
+        )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=3, layout=(4, 1))
+
+        box = df.boxplot(
+            column=["height", "weight", "category"], by="gender", layout=(-1, 1)
+        )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=3, layout=(3, 1))
+
+        box = df.groupby("classroom").boxplot(
+            column=["height", "weight", "category"], layout=(1, 4), return_type="dict"
+        )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=3, layout=(1, 4))
+
+        box = df.groupby("classroom").boxplot(  # noqa
+            column=["height", "weight", "category"], layout=(1, -1), return_type="dict"
+        )
+        self._check_axes_shape(self.plt.gcf().axes, axes_num=3, layout=(1, 3))
+
+    def test_grouped_box_multiple_axes(self):
+        # GH 6970, GH 7069
+        df = self.hist_df
+
+        # check warning to ignore sharex / sharey
+        # this check should be done in the first function which
+        # passes multiple axes to plot, hist or boxplot
+        # location should be changed if other test is added
+        # which has earlier alphabetical order
+        with tm.assert_produces_warning(UserWarning):
+            fig, axes = self.plt.subplots(2, 2)
+            df.groupby("category").boxplot(column="height", return_type="axes", ax=axes)
+            self._check_axes_shape(self.plt.gcf().axes, axes_num=4, layout=(2, 2))
+
+        fig, axes = self.plt.subplots(2, 3)
+        with tm.assert_produces_warning(UserWarning):
+            returned = df.boxplot(
+                column=["height", "weight", "category"],
+                by="gender",
+                return_type="axes",
+                ax=axes[0],
+            )
+        returned = np.array(list(returned.values))
+        self._check_axes_shape(returned, axes_num=3, layout=(1, 3))
+        tm.assert_numpy_array_equal(returned, axes[0])
+        assert returned[0].figure is fig
+
+        # draw on second row
+        with tm.assert_produces_warning(UserWarning):
+            returned = df.groupby("classroom").boxplot(
+                column=["height", "weight", "category"], return_type="axes", ax=axes[1]
+            )
+        returned = np.array(list(returned.values))
+        self._check_axes_shape(returned, axes_num=3, layout=(1, 3))
+        tm.assert_numpy_array_equal(returned, axes[1])
+        assert returned[0].figure is fig
+
+        msg = "The number of passed axes must be 3, the same as the output plot"
+        with pytest.raises(ValueError, match=msg):
+            fig, axes = self.plt.subplots(2, 3)
+            # pass different number of axes from required
+            with tm.assert_produces_warning(UserWarning):
+                axes = df.groupby("classroom").boxplot(ax=axes)
+
+    def test_fontsize(self):
+        df = DataFrame({"a": [1, 2, 3, 4, 5, 6], "b": [0, 0, 0, 1, 1, 1]})
+        self._check_ticks_props(
+            df.boxplot("a", by="b", fontsize=16), xlabelsize=16, ylabelsize=16
+        )
+
+    @pytest.mark.parametrize(
+        "col, expected_xticklabel",
+        [
+            ("v", ["(a, v)", "(b, v)", "(c, v)", "(d, v)", "(e, v)"]),
+            (["v"], ["(a, v)", "(b, v)", "(c, v)", "(d, v)", "(e, v)"]),
+            ("v1", ["(a, v1)", "(b, v1)", "(c, v1)", "(d, v1)", "(e, v1)"]),
+            (
+                ["v", "v1"],
+                [
+                    "(a, v)",
+                    "(a, v1)",
+                    "(b, v)",
+                    "(b, v1)",
+                    "(c, v)",
+                    "(c, v1)",
+                    "(d, v)",
+                    "(d, v1)",
+                    "(e, v)",
+                    "(e, v1)",
+                ],
+            ),
+            (
+                None,
+                [
+                    "(a, v)",
+                    "(a, v1)",
+                    "(b, v)",
+                    "(b, v1)",
+                    "(c, v)",
+                    "(c, v1)",
+                    "(d, v)",
+                    "(d, v1)",
+                    "(e, v)",
+                    "(e, v1)",
+                ],
+            ),
+        ],
+    )
+    def test_groupby_boxplot_subplots_false(self, col, expected_xticklabel):
+        # GH 16748
+        df = DataFrame(
+            {
+                "cat": np.random.choice(list("abcde"), 100),
+                "v": np.random.rand(100),
+                "v1": np.random.rand(100),
+            }
+        )
+        grouped = df.groupby("cat")
+
+        axes = _check_plot_works(
+            grouped.boxplot, subplots=False, column=col, return_type="axes"
+        )
+
+        result_xticklabel = [x.get_text() for x in axes.get_xticklabels()]
+        assert expected_xticklabel == result_xticklabel
+
+    def test_groupby_boxplot_object(self):
+        # GH 43480
+        df = self.hist_df.astype("object")
+        grouped = df.groupby("gender")
+        msg = "boxplot method requires numerical columns, nothing to plot"
+        with pytest.raises(ValueError, match=msg):
+            _check_plot_works(grouped.boxplot, subplots=False)
+
+    def test_boxplot_multiindex_column(self):
+        # GH 16748
+        arrays = [
+            ["bar", "bar", "baz", "baz", "foo", "foo", "qux", "qux"],
+            ["one", "two", "one", "two", "one", "two", "one", "two"],
+        ]
+        tuples = list(zip(*arrays))
+        index = MultiIndex.from_tuples(tuples, names=["first", "second"])
+        df = DataFrame(np.random.randn(3, 8), index=["A", "B", "C"], columns=index)
+
+        col = [("bar", "one"), ("bar", "two")]
+        axes = _check_plot_works(df.boxplot, column=col, return_type="axes")
+
+        expected_xticklabel = ["(bar, one)", "(bar, two)"]
+        result_xticklabel = [x.get_text() for x in axes.get_xticklabels()]
+        assert expected_xticklabel == result_xticklabel

.venv/Lib/site-packages/pandas/tests/plotting/test_common.py

@@ -0,0 +1,44 @@
+import pytest
+
+import pandas.util._test_decorators as td
+
+from pandas import DataFrame
+from pandas.tests.plotting.common import (
+    TestPlotBase,
+    _check_plot_works,
+    _gen_two_subplots,
+)
+
+pytestmark = pytest.mark.slow
+
+
+@td.skip_if_no_mpl
+class TestCommon(TestPlotBase):
+    def test__check_ticks_props(self):
+        # GH 34768
+        df = DataFrame({"b": [0, 1, 0], "a": [1, 2, 3]})
+        ax = _check_plot_works(df.plot, rot=30)
+        ax.yaxis.set_tick_params(rotation=30)
+        msg = "expected 0.00000 but got "
+        with pytest.raises(AssertionError, match=msg):
+            self._check_ticks_props(ax, xrot=0)
+        with pytest.raises(AssertionError, match=msg):
+            self._check_ticks_props(ax, xlabelsize=0)
+        with pytest.raises(AssertionError, match=msg):
+            self._check_ticks_props(ax, yrot=0)
+        with pytest.raises(AssertionError, match=msg):
+            self._check_ticks_props(ax, ylabelsize=0)
+
+    def test__gen_two_subplots_with_ax(self):
+        fig = self.plt.gcf()
+        gen = _gen_two_subplots(f=lambda **kwargs: None, fig=fig, ax="test")
+        # On the first yield, no subplot should be added since ax was passed
+        next(gen)
+        assert fig.get_axes() == []
+        # On the second, the one axis should match fig.subplot(2, 1, 2)
+        next(gen)
+        axes = fig.get_axes()
+        assert len(axes) == 1
+        subplot_geometry = list(axes[0].get_subplotspec().get_geometry()[:-1])
+        subplot_geometry[-1] += 1
+        assert subplot_geometry == [2, 1, 2]

.venv/Lib/site-packages/pandas/tests/plotting/test_converter.py

@@ -0,0 +1,384 @@
+from datetime import (
+    date,
+    datetime,
+)
+import subprocess
+import sys
+
+import numpy as np
+import pytest
+
+import pandas._config.config as cf
+
+import pandas.util._test_decorators as td
+
+from pandas import (
+    Index,
+    Period,
+    Series,
+    Timestamp,
+    date_range,
+)
+import pandas._testing as tm
+
+from pandas.plotting import (
+    deregister_matplotlib_converters,
+    register_matplotlib_converters,
+)
+from pandas.tseries.offsets import (
+    Day,
+    Micro,
+    Milli,
+    Second,
+)
+
+try:
+    from pandas.plotting._matplotlib import converter
+except ImportError:
+    # try / except, rather than skip, to avoid internal refactoring
+    # causing an improper skip
+    pass
+
+pytest.importorskip("matplotlib.pyplot")
+dates = pytest.importorskip("matplotlib.dates")
+
+
+pytestmark = pytest.mark.slow
+
+
+def test_registry_mpl_resets():
+    # Check that Matplotlib converters are properly reset (see issue #27481)
+    code = (
+        "import matplotlib.units as units; "
+        "import matplotlib.dates as mdates; "
+        "n_conv = len(units.registry); "
+        "import pandas as pd; "
+        "pd.plotting.register_matplotlib_converters(); "
+        "pd.plotting.deregister_matplotlib_converters(); "
+        "assert len(units.registry) == n_conv"
+    )
+    call = [sys.executable, "-c", code]
+    subprocess.check_output(call)
+
+
+def test_timtetonum_accepts_unicode():
+    assert converter.time2num("00:01") == converter.time2num("00:01")
+
+
+class TestRegistration:
+    def test_dont_register_by_default(self):
+        # Run in subprocess to ensure a clean state
+        code = (
+            "import matplotlib.units; "
+            "import pandas as pd; "
+            "units = dict(matplotlib.units.registry); "
+            "assert pd.Timestamp not in units"
+        )
+        call = [sys.executable, "-c", code]
+        assert subprocess.check_call(call) == 0
+
+    @td.skip_if_no("matplotlib", min_version="3.1.3")
+    def test_registering_no_warning(self):
+        plt = pytest.importorskip("matplotlib.pyplot")
+        s = Series(range(12), index=date_range("2017", periods=12))
+        _, ax = plt.subplots()
+
+        # Set to the "warn" state, in case this isn't the first test run
+        register_matplotlib_converters()
+        ax.plot(s.index, s.values)
+        plt.close()
+
+    def test_pandas_plots_register(self):
+        plt = pytest.importorskip("matplotlib.pyplot")
+        s = Series(range(12), index=date_range("2017", periods=12))
+        # Set to the "warn" state, in case this isn't the first test run
+        with tm.assert_produces_warning(None) as w:
+            s.plot()
+
+        try:
+            assert len(w) == 0
+        finally:
+            plt.close()
+
+    def test_matplotlib_formatters(self):
+        units = pytest.importorskip("matplotlib.units")
+
+        # Can't make any assertion about the start state.
+        # We we check that toggling converters off removes it, and toggling it
+        # on restores it.
+
+        with cf.option_context("plotting.matplotlib.register_converters", True):
+            with cf.option_context("plotting.matplotlib.register_converters", False):
+                assert Timestamp not in units.registry
+            assert Timestamp in units.registry
+
+    @td.skip_if_no("matplotlib", min_version="3.1.3")
+    def test_option_no_warning(self):
+        pytest.importorskip("matplotlib.pyplot")
+        ctx = cf.option_context("plotting.matplotlib.register_converters", False)
+        plt = pytest.importorskip("matplotlib.pyplot")
+        s = Series(range(12), index=date_range("2017", periods=12))
+        _, ax = plt.subplots()
+
+        # Test without registering first, no warning
+        with ctx:
+            ax.plot(s.index, s.values)
+
+        # Now test with registering
+        register_matplotlib_converters()
+        with ctx:
+            ax.plot(s.index, s.values)
+        plt.close()
+
+    def test_registry_resets(self):
+        units = pytest.importorskip("matplotlib.units")
+        dates = pytest.importorskip("matplotlib.dates")
+
+        # make a copy, to reset to
+        original = dict(units.registry)
+
+        try:
+            # get to a known state
+            units.registry.clear()
+            date_converter = dates.DateConverter()
+            units.registry[datetime] = date_converter
+            units.registry[date] = date_converter
+
+            register_matplotlib_converters()
+            assert units.registry[date] is not date_converter
+            deregister_matplotlib_converters()
+            assert units.registry[date] is date_converter
+
+        finally:
+            # restore original stater
+            units.registry.clear()
+            for k, v in original.items():
+                units.registry[k] = v
+
+
+class TestDateTimeConverter:
+    def setup_method(self, method):
+        self.dtc = converter.DatetimeConverter()
+        self.tc = converter.TimeFormatter(None)
+
+    def test_convert_accepts_unicode(self):
+        r1 = self.dtc.convert("12:22", None, None)
+        r2 = self.dtc.convert("12:22", None, None)
+        assert r1 == r2, "DatetimeConverter.convert should accept unicode"
+
+    def test_conversion(self):
+        rs = self.dtc.convert(["2012-1-1"], None, None)[0]
+        xp = dates.date2num(datetime(2012, 1, 1))
+        assert rs == xp
+
+        rs = self.dtc.convert("2012-1-1", None, None)
+        assert rs == xp
+
+        rs = self.dtc.convert(date(2012, 1, 1), None, None)
+        assert rs == xp
+
+        rs = self.dtc.convert("2012-1-1", None, None)
+        assert rs == xp
+
+        rs = self.dtc.convert(Timestamp("2012-1-1"), None, None)
+        assert rs == xp
+
+        # also testing datetime64 dtype (GH8614)
+        rs = self.dtc.convert("2012-01-01", None, None)
+        assert rs == xp
+
+        rs = self.dtc.convert("2012-01-01 00:00:00+0000", None, None)
+        assert rs == xp
+
+        rs = self.dtc.convert(
+            np.array(["2012-01-01 00:00:00+0000", "2012-01-02 00:00:00+0000"]),
+            None,
+            None,
+        )
+        assert rs[0] == xp
+
+        # we have a tz-aware date (constructed to that when we turn to utc it
+        # is the same as our sample)
+        ts = Timestamp("2012-01-01").tz_localize("UTC").tz_convert("US/Eastern")
+        rs = self.dtc.convert(ts, None, None)
+        assert rs == xp
+
+        rs = self.dtc.convert(ts.to_pydatetime(), None, None)
+        assert rs == xp
+
+        rs = self.dtc.convert(Index([ts - Day(1), ts]), None, None)
+        assert rs[1] == xp
+
+        rs = self.dtc.convert(Index([ts - Day(1), ts]).to_pydatetime(), None, None)
+        assert rs[1] == xp
+
+    def test_conversion_float(self):
+        rtol = 0.5 * 10**-9
+
+        rs = self.dtc.convert(Timestamp("2012-1-1 01:02:03", tz="UTC"), None, None)
+        xp = converter.dates.date2num(Timestamp("2012-1-1 01:02:03", tz="UTC"))
+        tm.assert_almost_equal(rs, xp, rtol=rtol)
+
+        rs = self.dtc.convert(
+            Timestamp("2012-1-1 09:02:03", tz="Asia/Hong_Kong"), None, None
+        )
+        tm.assert_almost_equal(rs, xp, rtol=rtol)
+
+        rs = self.dtc.convert(datetime(2012, 1, 1, 1, 2, 3), None, None)
+        tm.assert_almost_equal(rs, xp, rtol=rtol)
+
+    def test_conversion_outofbounds_datetime(self):
+        # 2579
+        values = [date(1677, 1, 1), date(1677, 1, 2)]
+        rs = self.dtc.convert(values, None, None)
+        xp = converter.dates.date2num(values)
+        tm.assert_numpy_array_equal(rs, xp)
+        rs = self.dtc.convert(values[0], None, None)
+        xp = converter.dates.date2num(values[0])
+        assert rs == xp
+
+        values = [datetime(1677, 1, 1, 12), datetime(1677, 1, 2, 12)]
+        rs = self.dtc.convert(values, None, None)
+        xp = converter.dates.date2num(values)
+        tm.assert_numpy_array_equal(rs, xp)
+        rs = self.dtc.convert(values[0], None, None)
+        xp = converter.dates.date2num(values[0])
+        assert rs == xp
+
+    @pytest.mark.parametrize(
+        "time,format_expected",
+        [
+            (0, "00:00"),  # time2num(datetime.time.min)
+            (86399.999999, "23:59:59.999999"),  # time2num(datetime.time.max)
+            (90000, "01:00"),
+            (3723, "01:02:03"),
+            (39723.2, "11:02:03.200"),
+        ],
+    )
+    def test_time_formatter(self, time, format_expected):
+        # issue 18478
+        result = self.tc(time)
+        assert result == format_expected
+
+    def test_dateindex_conversion(self):
+        rtol = 10**-9
+
+        for freq in ("B", "L", "S"):
+            dateindex = tm.makeDateIndex(k=10, freq=freq)
+            rs = self.dtc.convert(dateindex, None, None)
+            xp = converter.dates.date2num(dateindex._mpl_repr())
+            tm.assert_almost_equal(rs, xp, rtol=rtol)
+
+    def test_resolution(self):
+        def _assert_less(ts1, ts2):
+            val1 = self.dtc.convert(ts1, None, None)
+            val2 = self.dtc.convert(ts2, None, None)
+            if not val1 < val2:
+                raise AssertionError(f"{val1} is not less than {val2}.")
+
+        # Matplotlib's time representation using floats cannot distinguish
+        # intervals smaller than ~10 microsecond in the common range of years.
+        ts = Timestamp("2012-1-1")
+        _assert_less(ts, ts + Second())
+        _assert_less(ts, ts + Milli())
+        _assert_less(ts, ts + Micro(50))
+
+    def test_convert_nested(self):
+        inner = [Timestamp("2017-01-01"), Timestamp("2017-01-02")]
+        data = [inner, inner]
+        result = self.dtc.convert(data, None, None)
+        expected = [self.dtc.convert(x, None, None) for x in data]
+        assert (np.array(result) == expected).all()
+
+
+class TestPeriodConverter:
+    def setup_method(self, method):
+        self.pc = converter.PeriodConverter()
+
+        class Axis:
+            pass
+
+        self.axis = Axis()
+        self.axis.freq = "D"
+
+    def test_convert_accepts_unicode(self):
+        r1 = self.pc.convert("2012-1-1", None, self.axis)
+        r2 = self.pc.convert("2012-1-1", None, self.axis)
+        assert r1 == r2
+
+    def test_conversion(self):
+        rs = self.pc.convert(["2012-1-1"], None, self.axis)[0]
+        xp = Period("2012-1-1").ordinal
+        assert rs == xp
+
+        rs = self.pc.convert("2012-1-1", None, self.axis)
+        assert rs == xp
+
+        rs = self.pc.convert([date(2012, 1, 1)], None, self.axis)[0]
+        assert rs == xp
+
+        rs = self.pc.convert(date(2012, 1, 1), None, self.axis)
+        assert rs == xp
+
+        rs = self.pc.convert([Timestamp("2012-1-1")], None, self.axis)[0]
+        assert rs == xp
+
+        rs = self.pc.convert(Timestamp("2012-1-1"), None, self.axis)
+        assert rs == xp
+
+        rs = self.pc.convert("2012-01-01", None, self.axis)
+        assert rs == xp
+
+        rs = self.pc.convert("2012-01-01 00:00:00+0000", None, self.axis)
+        assert rs == xp
+
+        rs = self.pc.convert(
+            np.array(
+                ["2012-01-01 00:00:00", "2012-01-02 00:00:00"],
+                dtype="datetime64[ns]",
+            ),
+            None,
+            self.axis,
+        )
+        assert rs[0] == xp
+
+    def test_integer_passthrough(self):
+        # GH9012
+        rs = self.pc.convert([0, 1], None, self.axis)
+        xp = [0, 1]
+        assert rs == xp
+
+    def test_convert_nested(self):
+        data = ["2012-1-1", "2012-1-2"]
+        r1 = self.pc.convert([data, data], None, self.axis)
+        r2 = [self.pc.convert(data, None, self.axis) for _ in range(2)]
+        assert r1 == r2
+
+
+class TestTimeDeltaConverter:
+    """Test timedelta converter"""
+
+    @pytest.mark.parametrize(
+        "x, decimal, format_expected",
+        [
+            (0.0, 0, "00:00:00"),
+            (3972320000000, 1, "01:06:12.3"),
+            (713233432000000, 2, "8 days 06:07:13.43"),
+            (32423432000000, 4, "09:00:23.4320"),
+        ],
+    )
+    def test_format_timedelta_ticks(self, x, decimal, format_expected):
+        tdc = converter.TimeSeries_TimedeltaFormatter
+        result = tdc.format_timedelta_ticks(x, pos=None, n_decimals=decimal)
+        assert result == format_expected
+
+    @pytest.mark.parametrize("view_interval", [(1, 2), (2, 1)])
+    def test_call_w_different_view_intervals(self, view_interval, monkeypatch):
+        # previously broke on reversed xlmits; see GH37454
+        class mock_axis:
+            def get_view_interval(self):
+                return view_interval
+
+        tdc = converter.TimeSeries_TimedeltaFormatter()
+        monkeypatch.setattr(tdc, "axis", mock_axis())
+        tdc(0.0, 0)

.venv/Lib/site-packages/pandas/tests/plotting/test_groupby.py

@@ -0,0 +1,120 @@
+""" Test cases for GroupBy.plot """
+
+
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+from pandas import (
+    DataFrame,
+    Index,
+    Series,
+)
+import pandas._testing as tm
+from pandas.tests.plotting.common import TestPlotBase
+
+pytestmark = pytest.mark.slow
+
+
+@td.skip_if_no_mpl
+class TestDataFrameGroupByPlots(TestPlotBase):
+    def test_series_groupby_plotting_nominally_works(self):
+        n = 10
+        weight = Series(np.random.normal(166, 20, size=n))
+        height = Series(np.random.normal(60, 10, size=n))
+        with tm.RNGContext(42):
+            gender = np.random.choice(["male", "female"], size=n)
+
+        weight.groupby(gender).plot()
+        tm.close()
+        height.groupby(gender).hist()
+        tm.close()
+        # Regression test for GH8733
+        height.groupby(gender).plot(alpha=0.5)
+        tm.close()
+
+    def test_plotting_with_float_index_works(self):
+        # GH 7025
+        df = DataFrame(
+            {"def": [1, 1, 1, 2, 2, 2, 3, 3, 3], "val": np.random.randn(9)},
+            index=[1.0, 2.0, 3.0, 1.0, 2.0, 3.0, 1.0, 2.0, 3.0],
+        )
+
+        df.groupby("def")["val"].plot()
+        tm.close()
+        df.groupby("def")["val"].apply(lambda x: x.plot())
+        tm.close()
+
+    def test_hist_single_row(self):
+        # GH10214
+        bins = np.arange(80, 100 + 2, 1)
+        df = DataFrame({"Name": ["AAA", "BBB"], "ByCol": [1, 2], "Mark": [85, 89]})
+        df["Mark"].hist(by=df["ByCol"], bins=bins)
+        df = DataFrame({"Name": ["AAA"], "ByCol": [1], "Mark": [85]})
+        df["Mark"].hist(by=df["ByCol"], bins=bins)
+
+    def test_plot_submethod_works(self):
+        df = DataFrame({"x": [1, 2, 3, 4, 5], "y": [1, 2, 3, 2, 1], "z": list("ababa")})
+        df.groupby("z").plot.scatter("x", "y")
+        tm.close()
+        df.groupby("z")["x"].plot.line()
+        tm.close()
+
+    def test_plot_kwargs(self):
+
+        df = DataFrame({"x": [1, 2, 3, 4, 5], "y": [1, 2, 3, 2, 1], "z": list("ababa")})
+
+        res = df.groupby("z").plot(kind="scatter", x="x", y="y")
+        # check that a scatter plot is effectively plotted: the axes should
+        # contain a PathCollection from the scatter plot (GH11805)
+        assert len(res["a"].collections) == 1
+
+        res = df.groupby("z").plot.scatter(x="x", y="y")
+        assert len(res["a"].collections) == 1
+
+    @pytest.mark.parametrize("column, expected_axes_num", [(None, 2), ("b", 1)])
+    def test_groupby_hist_frame_with_legend(self, column, expected_axes_num):
+        # GH 6279 - DataFrameGroupBy histogram can have a legend
+        expected_layout = (1, expected_axes_num)
+        expected_labels = column or [["a"], ["b"]]
+
+        index = Index(15 * ["1"] + 15 * ["2"], name="c")
+        df = DataFrame(np.random.randn(30, 2), index=index, columns=["a", "b"])
+        g = df.groupby("c")
+
+        for axes in g.hist(legend=True, column=column):
+            self._check_axes_shape(
+                axes, axes_num=expected_axes_num, layout=expected_layout
+            )
+            for ax, expected_label in zip(axes[0], expected_labels):
+                self._check_legend_labels(ax, expected_label)
+
+    @pytest.mark.parametrize("column", [None, "b"])
+    def test_groupby_hist_frame_with_legend_raises(self, column):
+        # GH 6279 - DataFrameGroupBy histogram with legend and label raises
+        index = Index(15 * ["1"] + 15 * ["2"], name="c")
+        df = DataFrame(np.random.randn(30, 2), index=index, columns=["a", "b"])
+        g = df.groupby("c")
+
+        with pytest.raises(ValueError, match="Cannot use both legend and label"):
+            g.hist(legend=True, column=column, label="d")
+
+    def test_groupby_hist_series_with_legend(self):
+        # GH 6279 - SeriesGroupBy histogram can have a legend
+        index = Index(15 * ["1"] + 15 * ["2"], name="c")
+        df = DataFrame(np.random.randn(30, 2), index=index, columns=["a", "b"])
+        g = df.groupby("c")
+
+        for ax in g["a"].hist(legend=True):
+            self._check_axes_shape(ax, axes_num=1, layout=(1, 1))
+            self._check_legend_labels(ax, ["1", "2"])
+
+    def test_groupby_hist_series_with_legend_raises(self):
+        # GH 6279 - SeriesGroupBy histogram with legend and label raises
+        index = Index(15 * ["1"] + 15 * ["2"], name="c")
+        df = DataFrame(np.random.randn(30, 2), index=index, columns=["a", "b"])
+        g = df.groupby("c")
+
+        with pytest.raises(ValueError, match="Cannot use both legend and label"):
+            g.hist(legend=True, label="d")

.venv/Lib/site-packages/pandas/tests/plotting/test_hist_method.py

@@ -0,0 +1,774 @@
+""" Test cases for .hist method """
+import re
+
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+from pandas import (
+    DataFrame,
+    Index,
+    Series,
+    to_datetime,
+)
+import pandas._testing as tm
+from pandas.tests.plotting.common import (
+    TestPlotBase,
+    _check_plot_works,
+)
+
+pytestmark = pytest.mark.slow
+
+
+@td.skip_if_no_mpl
+class TestSeriesPlots(TestPlotBase):
+    def setup_method(self, method):
+        TestPlotBase.setup_method(self, method)
+        import matplotlib as mpl
+
+        mpl.rcdefaults()
+
+        self.ts = tm.makeTimeSeries()
+        self.ts.name = "ts"
+
+    def test_hist_legacy(self):
+        _check_plot_works(self.ts.hist)
+        _check_plot_works(self.ts.hist, grid=False)
+        _check_plot_works(self.ts.hist, figsize=(8, 10))
+        # _check_plot_works adds an ax so catch warning. see GH #13188
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(self.ts.hist, by=self.ts.index.month)
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(self.ts.hist, by=self.ts.index.month, bins=5)
+
+        fig, ax = self.plt.subplots(1, 1)
+        _check_plot_works(self.ts.hist, ax=ax, default_axes=True)
+        _check_plot_works(self.ts.hist, ax=ax, figure=fig, default_axes=True)
+        _check_plot_works(self.ts.hist, figure=fig, default_axes=True)
+        tm.close()
+
+        fig, (ax1, ax2) = self.plt.subplots(1, 2)
+        _check_plot_works(self.ts.hist, figure=fig, ax=ax1, default_axes=True)
+        _check_plot_works(self.ts.hist, figure=fig, ax=ax2, default_axes=True)
+
+        msg = (
+            "Cannot pass 'figure' when using the 'by' argument, since a new 'Figure' "
+            "instance will be created"
+        )
+        with pytest.raises(ValueError, match=msg):
+            self.ts.hist(by=self.ts.index, figure=fig)
+
+    def test_hist_bins_legacy(self):
+        df = DataFrame(np.random.randn(10, 2))
+        ax = df.hist(bins=2)[0][0]
+        assert len(ax.patches) == 2
+
+    def test_hist_layout(self):
+        df = self.hist_df
+        msg = "The 'layout' keyword is not supported when 'by' is None"
+        with pytest.raises(ValueError, match=msg):
+            df.height.hist(layout=(1, 1))
+
+        with pytest.raises(ValueError, match=msg):
+            df.height.hist(layout=[1, 1])
+
+    def test_hist_layout_with_by(self):
+        df = self.hist_df
+
+        # _check_plot_works adds an `ax` kwarg to the method call
+        # so we get a warning about an axis being cleared, even
+        # though we don't explicing pass one, see GH #13188
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.height.hist, by=df.gender, layout=(2, 1))
+        self._check_axes_shape(axes, axes_num=2, layout=(2, 1))
+
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.height.hist, by=df.gender, layout=(3, -1))
+        self._check_axes_shape(axes, axes_num=2, layout=(3, 1))
+
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.height.hist, by=df.category, layout=(4, 1))
+        self._check_axes_shape(axes, axes_num=4, layout=(4, 1))
+
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.height.hist, by=df.category, layout=(2, -1))
+        self._check_axes_shape(axes, axes_num=4, layout=(2, 2))
+
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.height.hist, by=df.category, layout=(3, -1))
+        self._check_axes_shape(axes, axes_num=4, layout=(3, 2))
+
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.height.hist, by=df.category, layout=(-1, 4))
+        self._check_axes_shape(axes, axes_num=4, layout=(1, 4))
+
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.height.hist, by=df.classroom, layout=(2, 2))
+        self._check_axes_shape(axes, axes_num=3, layout=(2, 2))
+
+        axes = df.height.hist(by=df.category, layout=(4, 2), figsize=(12, 7))
+        self._check_axes_shape(axes, axes_num=4, layout=(4, 2), figsize=(12, 7))
+
+    def test_hist_no_overlap(self):
+        from matplotlib.pyplot import (
+            gcf,
+            subplot,
+        )
+
+        x = Series(np.random.randn(2))
+        y = Series(np.random.randn(2))
+        subplot(121)
+        x.hist()
+        subplot(122)
+        y.hist()
+        fig = gcf()
+        axes = fig.axes
+        assert len(axes) == 2
+
+    def test_hist_by_no_extra_plots(self):
+        df = self.hist_df
+        axes = df.height.hist(by=df.gender)  # noqa
+        assert len(self.plt.get_fignums()) == 1
+
+    def test_plot_fails_when_ax_differs_from_figure(self):
+        from pylab import figure
+
+        fig1 = figure()
+        fig2 = figure()
+        ax1 = fig1.add_subplot(111)
+        msg = "passed axis not bound to passed figure"
+        with pytest.raises(AssertionError, match=msg):
+            self.ts.hist(ax=ax1, figure=fig2)
+
+    @pytest.mark.parametrize(
+        "histtype, expected",
+        [
+            ("bar", True),
+            ("barstacked", True),
+            ("step", False),
+            ("stepfilled", True),
+        ],
+    )
+    def test_histtype_argument(self, histtype, expected):
+        # GH23992 Verify functioning of histtype argument
+        ser = Series(np.random.randint(1, 10))
+        ax = ser.hist(histtype=histtype)
+        self._check_patches_all_filled(ax, filled=expected)
+
+    @pytest.mark.parametrize(
+        "by, expected_axes_num, expected_layout", [(None, 1, (1, 1)), ("b", 2, (1, 2))]
+    )
+    def test_hist_with_legend(self, by, expected_axes_num, expected_layout):
+        # GH 6279 - Series histogram can have a legend
+        index = 15 * ["1"] + 15 * ["2"]
+        s = Series(np.random.randn(30), index=index, name="a")
+        s.index.name = "b"
+
+        # Use default_axes=True when plotting method generate subplots itself
+        axes = _check_plot_works(s.hist, default_axes=True, legend=True, by=by)
+        self._check_axes_shape(axes, axes_num=expected_axes_num, layout=expected_layout)
+        self._check_legend_labels(axes, "a")
+
+    @pytest.mark.parametrize("by", [None, "b"])
+    def test_hist_with_legend_raises(self, by):
+        # GH 6279 - Series histogram with legend and label raises
+        index = 15 * ["1"] + 15 * ["2"]
+        s = Series(np.random.randn(30), index=index, name="a")
+        s.index.name = "b"
+
+        with pytest.raises(ValueError, match="Cannot use both legend and label"):
+            s.hist(legend=True, by=by, label="c")
+
+    def test_hist_kwargs(self):
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.hist(bins=5, ax=ax)
+        assert len(ax.patches) == 5
+        self._check_text_labels(ax.yaxis.get_label(), "Frequency")
+        tm.close()
+
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.hist(orientation="horizontal", ax=ax)
+        self._check_text_labels(ax.xaxis.get_label(), "Frequency")
+        tm.close()
+
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.hist(align="left", stacked=True, ax=ax)
+        tm.close()
+
+    @td.skip_if_no_scipy
+    def test_hist_kde(self):
+
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.hist(logy=True, ax=ax)
+        self._check_ax_scales(ax, yaxis="log")
+        xlabels = ax.get_xticklabels()
+        # ticks are values, thus ticklabels are blank
+        self._check_text_labels(xlabels, [""] * len(xlabels))
+        ylabels = ax.get_yticklabels()
+        self._check_text_labels(ylabels, [""] * len(ylabels))
+
+        _check_plot_works(self.ts.plot.kde)
+        _check_plot_works(self.ts.plot.density)
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.kde(logy=True, ax=ax)
+        self._check_ax_scales(ax, yaxis="log")
+        xlabels = ax.get_xticklabels()
+        self._check_text_labels(xlabels, [""] * len(xlabels))
+        ylabels = ax.get_yticklabels()
+        self._check_text_labels(ylabels, [""] * len(ylabels))
+
+    @td.skip_if_no_scipy
+    def test_hist_kde_color(self):
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.hist(logy=True, bins=10, color="b", ax=ax)
+        self._check_ax_scales(ax, yaxis="log")
+        assert len(ax.patches) == 10
+        self._check_colors(ax.patches, facecolors=["b"] * 10)
+
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.kde(logy=True, color="r", ax=ax)
+        self._check_ax_scales(ax, yaxis="log")
+        lines = ax.get_lines()
+        assert len(lines) == 1
+        self._check_colors(lines, ["r"])
+
+
+@td.skip_if_no_mpl
+class TestDataFramePlots(TestPlotBase):
+    def test_hist_df_legacy(self):
+        from matplotlib.patches import Rectangle
+
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(self.hist_df.hist)
+
+        # make sure layout is handled
+        df = DataFrame(np.random.randn(100, 2))
+        df[2] = to_datetime(
+            np.random.randint(
+                self.start_date_to_int64,
+                self.end_date_to_int64,
+                size=100,
+                dtype=np.int64,
+            )
+        )
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.hist, grid=False)
+        self._check_axes_shape(axes, axes_num=3, layout=(2, 2))
+        assert not axes[1, 1].get_visible()
+
+        _check_plot_works(df[[2]].hist)
+        df = DataFrame(np.random.randn(100, 1))
+        _check_plot_works(df.hist)
+
+        # make sure layout is handled
+        df = DataFrame(np.random.randn(100, 5))
+        df[5] = to_datetime(
+            np.random.randint(
+                self.start_date_to_int64,
+                self.end_date_to_int64,
+                size=100,
+                dtype=np.int64,
+            )
+        )
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.hist, layout=(4, 2))
+        self._check_axes_shape(axes, axes_num=6, layout=(4, 2))
+
+        # make sure sharex, sharey is handled
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(df.hist, sharex=True, sharey=True)
+
+        # handle figsize arg
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(df.hist, figsize=(8, 10))
+
+        # check bins argument
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(df.hist, bins=5)
+
+        # make sure xlabelsize and xrot are handled
+        ser = df[0]
+        xf, yf = 20, 18
+        xrot, yrot = 30, 40
+        axes = ser.hist(xlabelsize=xf, xrot=xrot, ylabelsize=yf, yrot=yrot)
+        self._check_ticks_props(
+            axes, xlabelsize=xf, xrot=xrot, ylabelsize=yf, yrot=yrot
+        )
+
+        xf, yf = 20, 18
+        xrot, yrot = 30, 40
+        axes = df.hist(xlabelsize=xf, xrot=xrot, ylabelsize=yf, yrot=yrot)
+        self._check_ticks_props(
+            axes, xlabelsize=xf, xrot=xrot, ylabelsize=yf, yrot=yrot
+        )
+
+        tm.close()
+
+        ax = ser.hist(cumulative=True, bins=4, density=True)
+        # height of last bin (index 5) must be 1.0
+        rects = [x for x in ax.get_children() if isinstance(x, Rectangle)]
+        tm.assert_almost_equal(rects[-1].get_height(), 1.0)
+
+        tm.close()
+        ax = ser.hist(log=True)
+        # scale of y must be 'log'
+        self._check_ax_scales(ax, yaxis="log")
+
+        tm.close()
+
+        # propagate attr exception from matplotlib.Axes.hist
+        with tm.external_error_raised(AttributeError):
+            ser.hist(foo="bar")
+
+    def test_hist_non_numerical_or_datetime_raises(self):
+        # gh-10444, GH32590
+        df = DataFrame(
+            {
+                "a": np.random.rand(10),
+                "b": np.random.randint(0, 10, 10),
+                "c": to_datetime(
+                    np.random.randint(
+                        1582800000000000000, 1583500000000000000, 10, dtype=np.int64
+                    )
+                ),
+                "d": to_datetime(
+                    np.random.randint(
+                        1582800000000000000, 1583500000000000000, 10, dtype=np.int64
+                    ),
+                    utc=True,
+                ),
+            }
+        )
+        df_o = df.astype(object)
+
+        msg = "hist method requires numerical or datetime columns, nothing to plot."
+        with pytest.raises(ValueError, match=msg):
+            df_o.hist()
+
+    def test_hist_layout(self):
+        df = DataFrame(np.random.randn(100, 2))
+        df[2] = to_datetime(
+            np.random.randint(
+                self.start_date_to_int64,
+                self.end_date_to_int64,
+                size=100,
+                dtype=np.int64,
+            )
+        )
+
+        layout_to_expected_size = (
+            {"layout": None, "expected_size": (2, 2)},  # default is 2x2
+            {"layout": (2, 2), "expected_size": (2, 2)},
+            {"layout": (4, 1), "expected_size": (4, 1)},
+            {"layout": (1, 4), "expected_size": (1, 4)},
+            {"layout": (3, 3), "expected_size": (3, 3)},
+            {"layout": (-1, 4), "expected_size": (1, 4)},
+            {"layout": (4, -1), "expected_size": (4, 1)},
+            {"layout": (-1, 2), "expected_size": (2, 2)},
+            {"layout": (2, -1), "expected_size": (2, 2)},
+        )
+
+        for layout_test in layout_to_expected_size:
+            axes = df.hist(layout=layout_test["layout"])
+            expected = layout_test["expected_size"]
+            self._check_axes_shape(axes, axes_num=3, layout=expected)
+
+        # layout too small for all 4 plots
+        msg = "Layout of 1x1 must be larger than required size 3"
+        with pytest.raises(ValueError, match=msg):
+            df.hist(layout=(1, 1))
+
+        # invalid format for layout
+        msg = re.escape("Layout must be a tuple of (rows, columns)")
+        with pytest.raises(ValueError, match=msg):
+            df.hist(layout=(1,))
+        msg = "At least one dimension of layout must be positive"
+        with pytest.raises(ValueError, match=msg):
+            df.hist(layout=(-1, -1))
+
+    # GH 9351
+    def test_tight_layout(self):
+        df = DataFrame(np.random.randn(100, 2))
+        df[2] = to_datetime(
+            np.random.randint(
+                self.start_date_to_int64,
+                self.end_date_to_int64,
+                size=100,
+                dtype=np.int64,
+            )
+        )
+        # Use default_axes=True when plotting method generate subplots itself
+        _check_plot_works(df.hist, default_axes=True)
+        self.plt.tight_layout()
+
+        tm.close()
+
+    def test_hist_subplot_xrot(self):
+        # GH 30288
+        df = DataFrame(
+            {
+                "length": [1.5, 0.5, 1.2, 0.9, 3],
+                "animal": ["pig", "rabbit", "pig", "pig", "rabbit"],
+            }
+        )
+        # Use default_axes=True when plotting method generate subplots itself
+        axes = _check_plot_works(
+            df.hist,
+            default_axes=True,
+            filterwarnings="always",
+            column="length",
+            by="animal",
+            bins=5,
+            xrot=0,
+        )
+        self._check_ticks_props(axes, xrot=0)
+
+    @pytest.mark.parametrize(
+        "column, expected",
+        [
+            (None, ["width", "length", "height"]),
+            (["length", "width", "height"], ["length", "width", "height"]),
+        ],
+    )
+    def test_hist_column_order_unchanged(self, column, expected):
+        # GH29235
+
+        df = DataFrame(
+            {
+                "width": [0.7, 0.2, 0.15, 0.2, 1.1],
+                "length": [1.5, 0.5, 1.2, 0.9, 3],
+                "height": [3, 0.5, 3.4, 2, 1],
+            },
+            index=["pig", "rabbit", "duck", "chicken", "horse"],
+        )
+
+        # Use default_axes=True when plotting method generate subplots itself
+        axes = _check_plot_works(
+            df.hist,
+            default_axes=True,
+            column=column,
+            layout=(1, 3),
+        )
+        result = [axes[0, i].get_title() for i in range(3)]
+        assert result == expected
+
+    @pytest.mark.parametrize(
+        "histtype, expected",
+        [
+            ("bar", True),
+            ("barstacked", True),
+            ("step", False),
+            ("stepfilled", True),
+        ],
+    )
+    def test_histtype_argument(self, histtype, expected):
+        # GH23992 Verify functioning of histtype argument
+        df = DataFrame(np.random.randint(1, 10, size=(100, 2)), columns=["a", "b"])
+        ax = df.hist(histtype=histtype)
+        self._check_patches_all_filled(ax, filled=expected)
+
+    @pytest.mark.parametrize("by", [None, "c"])
+    @pytest.mark.parametrize("column", [None, "b"])
+    def test_hist_with_legend(self, by, column):
+        # GH 6279 - DataFrame histogram can have a legend
+        expected_axes_num = 1 if by is None and column is not None else 2
+        expected_layout = (1, expected_axes_num)
+        expected_labels = column or ["a", "b"]
+        if by is not None:
+            expected_labels = [expected_labels] * 2
+
+        index = Index(15 * ["1"] + 15 * ["2"], name="c")
+        df = DataFrame(np.random.randn(30, 2), index=index, columns=["a", "b"])
+
+        # Use default_axes=True when plotting method generate subplots itself
+        axes = _check_plot_works(
+            df.hist,
+            default_axes=True,
+            legend=True,
+            by=by,
+            column=column,
+        )
+
+        self._check_axes_shape(axes, axes_num=expected_axes_num, layout=expected_layout)
+        if by is None and column is None:
+            axes = axes[0]
+        for expected_label, ax in zip(expected_labels, axes):
+            self._check_legend_labels(ax, expected_label)
+
+    @pytest.mark.parametrize("by", [None, "c"])
+    @pytest.mark.parametrize("column", [None, "b"])
+    def test_hist_with_legend_raises(self, by, column):
+        # GH 6279 - DataFrame histogram with legend and label raises
+        index = Index(15 * ["1"] + 15 * ["2"], name="c")
+        df = DataFrame(np.random.randn(30, 2), index=index, columns=["a", "b"])
+
+        with pytest.raises(ValueError, match="Cannot use both legend and label"):
+            df.hist(legend=True, by=by, column=column, label="d")
+
+    def test_hist_df_kwargs(self):
+        df = DataFrame(np.random.randn(10, 2))
+        _, ax = self.plt.subplots()
+        ax = df.plot.hist(bins=5, ax=ax)
+        assert len(ax.patches) == 10
+
+    def test_hist_df_with_nonnumerics(self):
+        # GH 9853
+        with tm.RNGContext(1):
+            df = DataFrame(np.random.randn(10, 4), columns=["A", "B", "C", "D"])
+        df["E"] = ["x", "y"] * 5
+        _, ax = self.plt.subplots()
+        ax = df.plot.hist(bins=5, ax=ax)
+        assert len(ax.patches) == 20
+
+        _, ax = self.plt.subplots()
+        ax = df.plot.hist(ax=ax)  # bins=10
+        assert len(ax.patches) == 40
+
+    def test_hist_secondary_legend(self):
+        # GH 9610
+        df = DataFrame(np.random.randn(30, 4), columns=list("abcd"))
+
+        # primary -> secondary
+        _, ax = self.plt.subplots()
+        ax = df["a"].plot.hist(legend=True, ax=ax)
+        df["b"].plot.hist(ax=ax, legend=True, secondary_y=True)
+        # both legends are drawn on left ax
+        # left and right axis must be visible
+        self._check_legend_labels(ax, labels=["a", "b (right)"])
+        assert ax.get_yaxis().get_visible()
+        assert ax.right_ax.get_yaxis().get_visible()
+        tm.close()
+
+        # secondary -> secondary
+        _, ax = self.plt.subplots()
+        ax = df["a"].plot.hist(legend=True, secondary_y=True, ax=ax)
+        df["b"].plot.hist(ax=ax, legend=True, secondary_y=True)
+        # both legends are draw on left ax
+        # left axis must be invisible, right axis must be visible
+        self._check_legend_labels(ax.left_ax, labels=["a (right)", "b (right)"])
+        assert not ax.left_ax.get_yaxis().get_visible()
+        assert ax.get_yaxis().get_visible()
+        tm.close()
+
+        # secondary -> primary
+        _, ax = self.plt.subplots()
+        ax = df["a"].plot.hist(legend=True, secondary_y=True, ax=ax)
+        # right axes is returned
+        df["b"].plot.hist(ax=ax, legend=True)
+        # both legends are draw on left ax
+        # left and right axis must be visible
+        self._check_legend_labels(ax.left_ax, labels=["a (right)", "b"])
+        assert ax.left_ax.get_yaxis().get_visible()
+        assert ax.get_yaxis().get_visible()
+        tm.close()
+
+
+@td.skip_if_no_mpl
+class TestDataFrameGroupByPlots(TestPlotBase):
+    def test_grouped_hist_legacy(self):
+        from matplotlib.patches import Rectangle
+
+        from pandas.plotting._matplotlib.hist import _grouped_hist
+
+        df = DataFrame(np.random.randn(500, 1), columns=["A"])
+        df["B"] = to_datetime(
+            np.random.randint(
+                self.start_date_to_int64,
+                self.end_date_to_int64,
+                size=500,
+                dtype=np.int64,
+            )
+        )
+        df["C"] = np.random.randint(0, 4, 500)
+        df["D"] = ["X"] * 500
+
+        axes = _grouped_hist(df.A, by=df.C)
+        self._check_axes_shape(axes, axes_num=4, layout=(2, 2))
+
+        tm.close()
+        axes = df.hist(by=df.C)
+        self._check_axes_shape(axes, axes_num=4, layout=(2, 2))
+
+        tm.close()
+        # group by a key with single value
+        axes = df.hist(by="D", rot=30)
+        self._check_axes_shape(axes, axes_num=1, layout=(1, 1))
+        self._check_ticks_props(axes, xrot=30)
+
+        tm.close()
+        # make sure kwargs to hist are handled
+        xf, yf = 20, 18
+        xrot, yrot = 30, 40
+
+        axes = _grouped_hist(
+            df.A,
+            by=df.C,
+            cumulative=True,
+            bins=4,
+            xlabelsize=xf,
+            xrot=xrot,
+            ylabelsize=yf,
+            yrot=yrot,
+            density=True,
+        )
+        # height of last bin (index 5) must be 1.0
+        for ax in axes.ravel():
+            rects = [x for x in ax.get_children() if isinstance(x, Rectangle)]
+            height = rects[-1].get_height()
+            tm.assert_almost_equal(height, 1.0)
+        self._check_ticks_props(
+            axes, xlabelsize=xf, xrot=xrot, ylabelsize=yf, yrot=yrot
+        )
+
+        tm.close()
+        axes = _grouped_hist(df.A, by=df.C, log=True)
+        # scale of y must be 'log'
+        self._check_ax_scales(axes, yaxis="log")
+
+        tm.close()
+        # propagate attr exception from matplotlib.Axes.hist
+        with tm.external_error_raised(AttributeError):
+            _grouped_hist(df.A, by=df.C, foo="bar")
+
+        msg = "Specify figure size by tuple instead"
+        with pytest.raises(ValueError, match=msg):
+            df.hist(by="C", figsize="default")
+
+    def test_grouped_hist_legacy2(self):
+        n = 10
+        weight = Series(np.random.normal(166, 20, size=n))
+        height = Series(np.random.normal(60, 10, size=n))
+        with tm.RNGContext(42):
+            gender_int = np.random.choice([0, 1], size=n)
+        df_int = DataFrame({"height": height, "weight": weight, "gender": gender_int})
+        gb = df_int.groupby("gender")
+        axes = gb.hist()
+        assert len(axes) == 2
+        assert len(self.plt.get_fignums()) == 2
+        tm.close()
+
+    def test_grouped_hist_layout(self):
+        df = self.hist_df
+        msg = "Layout of 1x1 must be larger than required size 2"
+        with pytest.raises(ValueError, match=msg):
+            df.hist(column="weight", by=df.gender, layout=(1, 1))
+
+        msg = "Layout of 1x3 must be larger than required size 4"
+        with pytest.raises(ValueError, match=msg):
+            df.hist(column="height", by=df.category, layout=(1, 3))
+
+        msg = "At least one dimension of layout must be positive"
+        with pytest.raises(ValueError, match=msg):
+            df.hist(column="height", by=df.category, layout=(-1, -1))
+
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(
+                df.hist, column="height", by=df.gender, layout=(2, 1)
+            )
+        self._check_axes_shape(axes, axes_num=2, layout=(2, 1))
+
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(
+                df.hist, column="height", by=df.gender, layout=(2, -1)
+            )
+        self._check_axes_shape(axes, axes_num=2, layout=(2, 1))
+
+        axes = df.hist(column="height", by=df.category, layout=(4, 1))
+        self._check_axes_shape(axes, axes_num=4, layout=(4, 1))
+
+        axes = df.hist(column="height", by=df.category, layout=(-1, 1))
+        self._check_axes_shape(axes, axes_num=4, layout=(4, 1))
+
+        axes = df.hist(column="height", by=df.category, layout=(4, 2), figsize=(12, 8))
+        self._check_axes_shape(axes, axes_num=4, layout=(4, 2), figsize=(12, 8))
+        tm.close()
+
+        # GH 6769
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(
+                df.hist, column="height", by="classroom", layout=(2, 2)
+            )
+        self._check_axes_shape(axes, axes_num=3, layout=(2, 2))
+
+        # without column
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(df.hist, by="classroom")
+        self._check_axes_shape(axes, axes_num=3, layout=(2, 2))
+
+        axes = df.hist(by="gender", layout=(3, 5))
+        self._check_axes_shape(axes, axes_num=2, layout=(3, 5))
+
+        axes = df.hist(column=["height", "weight", "category"])
+        self._check_axes_shape(axes, axes_num=3, layout=(2, 2))
+
+    def test_grouped_hist_multiple_axes(self):
+        # GH 6970, GH 7069
+        df = self.hist_df
+
+        fig, axes = self.plt.subplots(2, 3)
+        returned = df.hist(column=["height", "weight", "category"], ax=axes[0])
+        self._check_axes_shape(returned, axes_num=3, layout=(1, 3))
+        tm.assert_numpy_array_equal(returned, axes[0])
+        assert returned[0].figure is fig
+        returned = df.hist(by="classroom", ax=axes[1])
+        self._check_axes_shape(returned, axes_num=3, layout=(1, 3))
+        tm.assert_numpy_array_equal(returned, axes[1])
+        assert returned[0].figure is fig
+
+        fig, axes = self.plt.subplots(2, 3)
+        # pass different number of axes from required
+        msg = "The number of passed axes must be 1, the same as the output plot"
+        with pytest.raises(ValueError, match=msg):
+            axes = df.hist(column="height", ax=axes)
+
+    def test_axis_share_x(self):
+        df = self.hist_df
+        # GH4089
+        ax1, ax2 = df.hist(column="height", by=df.gender, sharex=True)
+
+        # share x
+        assert self.get_x_axis(ax1).joined(ax1, ax2)
+        assert self.get_x_axis(ax2).joined(ax1, ax2)
+
+        # don't share y
+        assert not self.get_y_axis(ax1).joined(ax1, ax2)
+        assert not self.get_y_axis(ax2).joined(ax1, ax2)
+
+    def test_axis_share_y(self):
+        df = self.hist_df
+        ax1, ax2 = df.hist(column="height", by=df.gender, sharey=True)
+
+        # share y
+        assert self.get_y_axis(ax1).joined(ax1, ax2)
+        assert self.get_y_axis(ax2).joined(ax1, ax2)
+
+        # don't share x
+        assert not self.get_x_axis(ax1).joined(ax1, ax2)
+        assert not self.get_x_axis(ax2).joined(ax1, ax2)
+
+    def test_axis_share_xy(self):
+        df = self.hist_df
+        ax1, ax2 = df.hist(column="height", by=df.gender, sharex=True, sharey=True)
+
+        # share both x and y
+        assert self.get_x_axis(ax1).joined(ax1, ax2)
+        assert self.get_x_axis(ax2).joined(ax1, ax2)
+
+        assert self.get_y_axis(ax1).joined(ax1, ax2)
+        assert self.get_y_axis(ax2).joined(ax1, ax2)
+
+    @pytest.mark.parametrize(
+        "histtype, expected",
+        [
+            ("bar", True),
+            ("barstacked", True),
+            ("step", False),
+            ("stepfilled", True),
+        ],
+    )
+    def test_histtype_argument(self, histtype, expected):
+        # GH23992 Verify functioning of histtype argument
+        df = DataFrame(np.random.randint(1, 10, size=(100, 2)), columns=["a", "b"])
+        ax = df.hist(by="a", histtype=histtype)
+        self._check_patches_all_filled(ax, filled=expected)

.venv/Lib/site-packages/pandas/tests/plotting/test_misc.py

@@ -0,0 +1,561 @@
+""" Test cases for misc plot functions """
+
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+from pandas import (
+    DataFrame,
+    Series,
+)
+import pandas._testing as tm
+from pandas.tests.plotting.common import (
+    TestPlotBase,
+    _check_plot_works,
+)
+
+import pandas.plotting as plotting
+
+pytestmark = pytest.mark.slow
+
+
+@td.skip_if_mpl
+def test_import_error_message():
+    # GH-19810
+    df = DataFrame({"A": [1, 2]})
+
+    with pytest.raises(ImportError, match="matplotlib is required for plotting"):
+        df.plot()
+
+
+def test_get_accessor_args():
+    func = plotting._core.PlotAccessor._get_call_args
+
+    msg = "Called plot accessor for type list, expected Series or DataFrame"
+    with pytest.raises(TypeError, match=msg):
+        func(backend_name="", data=[], args=[], kwargs={})
+
+    msg = "should not be called with positional arguments"
+    with pytest.raises(TypeError, match=msg):
+        func(backend_name="", data=Series(dtype=object), args=["line", None], kwargs={})
+
+    x, y, kind, kwargs = func(
+        backend_name="",
+        data=DataFrame(),
+        args=["x"],
+        kwargs={"y": "y", "kind": "bar", "grid": False},
+    )
+    assert x == "x"
+    assert y == "y"
+    assert kind == "bar"
+    assert kwargs == {"grid": False}
+
+    x, y, kind, kwargs = func(
+        backend_name="pandas.plotting._matplotlib",
+        data=Series(dtype=object),
+        args=[],
+        kwargs={},
+    )
+    assert x is None
+    assert y is None
+    assert kind == "line"
+    assert len(kwargs) == 24
+
+
+@td.skip_if_no_mpl
+class TestSeriesPlots(TestPlotBase):
+    def setup_method(self, method):
+        TestPlotBase.setup_method(self, method)
+        import matplotlib as mpl
+
+        mpl.rcdefaults()
+
+        self.ts = tm.makeTimeSeries()
+        self.ts.name = "ts"
+
+    def test_autocorrelation_plot(self):
+        from pandas.plotting import autocorrelation_plot
+
+        # Ensure no UserWarning when making plot
+        with tm.assert_produces_warning(None):
+            _check_plot_works(autocorrelation_plot, series=self.ts)
+            _check_plot_works(autocorrelation_plot, series=self.ts.values)
+
+            ax = autocorrelation_plot(self.ts, label="Test")
+        self._check_legend_labels(ax, labels=["Test"])
+
+    def test_lag_plot(self):
+        from pandas.plotting import lag_plot
+
+        _check_plot_works(lag_plot, series=self.ts)
+        _check_plot_works(lag_plot, series=self.ts, lag=5)
+
+    def test_bootstrap_plot(self):
+        from pandas.plotting import bootstrap_plot
+
+        _check_plot_works(bootstrap_plot, series=self.ts, size=10)
+
+
+@td.skip_if_no_mpl
+class TestDataFramePlots(TestPlotBase):
+    @td.skip_if_no_scipy
+    @pytest.mark.parametrize("pass_axis", [False, True])
+    def test_scatter_matrix_axis(self, pass_axis):
+        from pandas.plotting._matplotlib.compat import mpl_ge_3_0_0
+
+        scatter_matrix = plotting.scatter_matrix
+
+        ax = None
+        if pass_axis:
+            _, ax = self.plt.subplots(3, 3)
+
+        with tm.RNGContext(42):
+            df = DataFrame(np.random.randn(100, 3))
+
+        # we are plotting multiples on a sub-plot
+        with tm.assert_produces_warning(
+            UserWarning, raise_on_extra_warnings=mpl_ge_3_0_0()
+        ):
+            axes = _check_plot_works(
+                scatter_matrix,
+                filterwarnings="always",
+                frame=df,
+                range_padding=0.1,
+                ax=ax,
+            )
+        axes0_labels = axes[0][0].yaxis.get_majorticklabels()
+
+        # GH 5662
+        expected = ["-2", "0", "2"]
+        self._check_text_labels(axes0_labels, expected)
+        self._check_ticks_props(axes, xlabelsize=8, xrot=90, ylabelsize=8, yrot=0)
+
+        df[0] = (df[0] - 2) / 3
+
+        # we are plotting multiples on a sub-plot
+        with tm.assert_produces_warning(UserWarning):
+            axes = _check_plot_works(
+                scatter_matrix,
+                filterwarnings="always",
+                frame=df,
+                range_padding=0.1,
+                ax=ax,
+            )
+        axes0_labels = axes[0][0].yaxis.get_majorticklabels()
+        expected = ["-1.0", "-0.5", "0.0"]
+        self._check_text_labels(axes0_labels, expected)
+        self._check_ticks_props(axes, xlabelsize=8, xrot=90, ylabelsize=8, yrot=0)
+
+    def test_andrews_curves(self, iris):
+        from matplotlib import cm
+
+        from pandas.plotting import andrews_curves
+
+        df = iris
+        # Ensure no UserWarning when making plot
+        with tm.assert_produces_warning(None):
+            _check_plot_works(andrews_curves, frame=df, class_column="Name")
+
+        rgba = ("#556270", "#4ECDC4", "#C7F464")
+        ax = _check_plot_works(
+            andrews_curves, frame=df, class_column="Name", color=rgba
+        )
+        self._check_colors(
+            ax.get_lines()[:10], linecolors=rgba, mapping=df["Name"][:10]
+        )
+
+        cnames = ["dodgerblue", "aquamarine", "seagreen"]
+        ax = _check_plot_works(
+            andrews_curves, frame=df, class_column="Name", color=cnames
+        )
+        self._check_colors(
+            ax.get_lines()[:10], linecolors=cnames, mapping=df["Name"][:10]
+        )
+
+        ax = _check_plot_works(
+            andrews_curves, frame=df, class_column="Name", colormap=cm.jet
+        )
+        cmaps = [cm.jet(n) for n in np.linspace(0, 1, df["Name"].nunique())]
+        self._check_colors(
+            ax.get_lines()[:10], linecolors=cmaps, mapping=df["Name"][:10]
+        )
+
+        length = 10
+        df = DataFrame(
+            {
+                "A": np.random.rand(length),
+                "B": np.random.rand(length),
+                "C": np.random.rand(length),
+                "Name": ["A"] * length,
+            }
+        )
+
+        _check_plot_works(andrews_curves, frame=df, class_column="Name")
+
+        rgba = ("#556270", "#4ECDC4", "#C7F464")
+        ax = _check_plot_works(
+            andrews_curves, frame=df, class_column="Name", color=rgba
+        )
+        self._check_colors(
+            ax.get_lines()[:10], linecolors=rgba, mapping=df["Name"][:10]
+        )
+
+        cnames = ["dodgerblue", "aquamarine", "seagreen"]
+        ax = _check_plot_works(
+            andrews_curves, frame=df, class_column="Name", color=cnames
+        )
+        self._check_colors(
+            ax.get_lines()[:10], linecolors=cnames, mapping=df["Name"][:10]
+        )
+
+        ax = _check_plot_works(
+            andrews_curves, frame=df, class_column="Name", colormap=cm.jet
+        )
+        cmaps = [cm.jet(n) for n in np.linspace(0, 1, df["Name"].nunique())]
+        self._check_colors(
+            ax.get_lines()[:10], linecolors=cmaps, mapping=df["Name"][:10]
+        )
+
+        colors = ["b", "g", "r"]
+        df = DataFrame({"A": [1, 2, 3], "B": [1, 2, 3], "C": [1, 2, 3], "Name": colors})
+        ax = andrews_curves(df, "Name", color=colors)
+        handles, labels = ax.get_legend_handles_labels()
+        self._check_colors(handles, linecolors=colors)
+
+    def test_parallel_coordinates(self, iris):
+        from matplotlib import cm
+
+        from pandas.plotting import parallel_coordinates
+
+        df = iris
+
+        ax = _check_plot_works(parallel_coordinates, frame=df, class_column="Name")
+        nlines = len(ax.get_lines())
+        nxticks = len(ax.xaxis.get_ticklabels())
+
+        rgba = ("#556270", "#4ECDC4", "#C7F464")
+        ax = _check_plot_works(
+            parallel_coordinates, frame=df, class_column="Name", color=rgba
+        )
+        self._check_colors(
+            ax.get_lines()[:10], linecolors=rgba, mapping=df["Name"][:10]
+        )
+
+        cnames = ["dodgerblue", "aquamarine", "seagreen"]
+        ax = _check_plot_works(
+            parallel_coordinates, frame=df, class_column="Name", color=cnames
+        )
+        self._check_colors(
+            ax.get_lines()[:10], linecolors=cnames, mapping=df["Name"][:10]
+        )
+
+        ax = _check_plot_works(
+            parallel_coordinates, frame=df, class_column="Name", colormap=cm.jet
+        )
+        cmaps = [cm.jet(n) for n in np.linspace(0, 1, df["Name"].nunique())]
+        self._check_colors(
+            ax.get_lines()[:10], linecolors=cmaps, mapping=df["Name"][:10]
+        )
+
+        ax = _check_plot_works(
+            parallel_coordinates, frame=df, class_column="Name", axvlines=False
+        )
+        assert len(ax.get_lines()) == (nlines - nxticks)
+
+        colors = ["b", "g", "r"]
+        df = DataFrame({"A": [1, 2, 3], "B": [1, 2, 3], "C": [1, 2, 3], "Name": colors})
+        ax = parallel_coordinates(df, "Name", color=colors)
+        handles, labels = ax.get_legend_handles_labels()
+        self._check_colors(handles, linecolors=colors)
+
+    # not sure if this is indicative of a problem
+    @pytest.mark.filterwarnings("ignore:Attempting to set:UserWarning")
+    def test_parallel_coordinates_with_sorted_labels(self):
+        """For #15908"""
+        from pandas.plotting import parallel_coordinates
+
+        df = DataFrame(
+            {
+                "feat": list(range(30)),
+                "class": [2 for _ in range(10)]
+                + [3 for _ in range(10)]
+                + [1 for _ in range(10)],
+            }
+        )
+        ax = parallel_coordinates(df, "class", sort_labels=True)
+        polylines, labels = ax.get_legend_handles_labels()
+        color_label_tuples = zip(
+            [polyline.get_color() for polyline in polylines], labels
+        )
+        ordered_color_label_tuples = sorted(color_label_tuples, key=lambda x: x[1])
+        prev_next_tupels = zip(
+            list(ordered_color_label_tuples[0:-1]), list(ordered_color_label_tuples[1:])
+        )
+        for prev, nxt in prev_next_tupels:
+            # labels and colors are ordered strictly increasing
+            assert prev[1] < nxt[1] and prev[0] < nxt[0]
+
+    def test_radviz(self, iris):
+        from matplotlib import cm
+
+        from pandas.plotting import radviz
+
+        df = iris
+        # Ensure no UserWarning when making plot
+        with tm.assert_produces_warning(None):
+            _check_plot_works(radviz, frame=df, class_column="Name")
+
+        rgba = ("#556270", "#4ECDC4", "#C7F464")
+        ax = _check_plot_works(radviz, frame=df, class_column="Name", color=rgba)
+        # skip Circle drawn as ticks
+        patches = [p for p in ax.patches[:20] if p.get_label() != ""]
+        self._check_colors(patches[:10], facecolors=rgba, mapping=df["Name"][:10])
+
+        cnames = ["dodgerblue", "aquamarine", "seagreen"]
+        _check_plot_works(radviz, frame=df, class_column="Name", color=cnames)
+        patches = [p for p in ax.patches[:20] if p.get_label() != ""]
+        self._check_colors(patches, facecolors=cnames, mapping=df["Name"][:10])
+
+        _check_plot_works(radviz, frame=df, class_column="Name", colormap=cm.jet)
+        cmaps = [cm.jet(n) for n in np.linspace(0, 1, df["Name"].nunique())]
+        patches = [p for p in ax.patches[:20] if p.get_label() != ""]
+        self._check_colors(patches, facecolors=cmaps, mapping=df["Name"][:10])
+
+        colors = [[0.0, 0.0, 1.0, 1.0], [0.0, 0.5, 1.0, 1.0], [1.0, 0.0, 0.0, 1.0]]
+        df = DataFrame(
+            {"A": [1, 2, 3], "B": [2, 1, 3], "C": [3, 2, 1], "Name": ["b", "g", "r"]}
+        )
+        ax = radviz(df, "Name", color=colors)
+        handles, labels = ax.get_legend_handles_labels()
+        self._check_colors(handles, facecolors=colors)
+
+    def test_subplot_titles(self, iris):
+        df = iris.drop("Name", axis=1).head()
+        # Use the column names as the subplot titles
+        title = list(df.columns)
+
+        # Case len(title) == len(df)
+        plot = df.plot(subplots=True, title=title)
+        assert [p.get_title() for p in plot] == title
+
+        # Case len(title) > len(df)
+        msg = (
+            "The length of `title` must equal the number of columns if "
+            "using `title` of type `list` and `subplots=True`"
+        )
+        with pytest.raises(ValueError, match=msg):
+            df.plot(subplots=True, title=title + ["kittens > puppies"])
+
+        # Case len(title) < len(df)
+        with pytest.raises(ValueError, match=msg):
+            df.plot(subplots=True, title=title[:2])
+
+        # Case subplots=False and title is of type list
+        msg = (
+            "Using `title` of type `list` is not supported unless "
+            "`subplots=True` is passed"
+        )
+        with pytest.raises(ValueError, match=msg):
+            df.plot(subplots=False, title=title)
+
+        # Case df with 3 numeric columns but layout of (2,2)
+        plot = df.drop("SepalWidth", axis=1).plot(
+            subplots=True, layout=(2, 2), title=title[:-1]
+        )
+        title_list = [ax.get_title() for sublist in plot for ax in sublist]
+        assert title_list == title[:3] + [""]
+
+    def test_get_standard_colors_random_seed(self):
+        # GH17525
+        df = DataFrame(np.zeros((10, 10)))
+
+        # Make sure that the np.random.seed isn't reset by get_standard_colors
+        plotting.parallel_coordinates(df, 0)
+        rand1 = np.random.random()
+        plotting.parallel_coordinates(df, 0)
+        rand2 = np.random.random()
+        assert rand1 != rand2
+
+        # Make sure it produces the same colors every time it's called
+        from pandas.plotting._matplotlib.style import get_standard_colors
+
+        color1 = get_standard_colors(1, color_type="random")
+        color2 = get_standard_colors(1, color_type="random")
+        assert color1 == color2
+
+    def test_get_standard_colors_default_num_colors(self):
+        from pandas.plotting._matplotlib.style import get_standard_colors
+
+        # Make sure the default color_types returns the specified amount
+        color1 = get_standard_colors(1, color_type="default")
+        color2 = get_standard_colors(9, color_type="default")
+        color3 = get_standard_colors(20, color_type="default")
+        assert len(color1) == 1
+        assert len(color2) == 9
+        assert len(color3) == 20
+
+    def test_plot_single_color(self):
+        # Example from #20585. All 3 bars should have the same color
+        df = DataFrame(
+            {
+                "account-start": ["2017-02-03", "2017-03-03", "2017-01-01"],
+                "client": ["Alice Anders", "Bob Baker", "Charlie Chaplin"],
+                "balance": [-1432.32, 10.43, 30000.00],
+                "db-id": [1234, 2424, 251],
+                "proxy-id": [525, 1525, 2542],
+                "rank": [52, 525, 32],
+            }
+        )
+        ax = df.client.value_counts().plot.bar()
+        colors = [rect.get_facecolor() for rect in ax.get_children()[0:3]]
+        assert all(color == colors[0] for color in colors)
+
+    def test_get_standard_colors_no_appending(self):
+        # GH20726
+
+        # Make sure not to add more colors so that matplotlib can cycle
+        # correctly.
+        from matplotlib import cm
+
+        from pandas.plotting._matplotlib.style import get_standard_colors
+
+        color_before = cm.gnuplot(range(5))
+        color_after = get_standard_colors(1, color=color_before)
+        assert len(color_after) == len(color_before)
+
+        df = DataFrame(np.random.randn(48, 4), columns=list("ABCD"))
+
+        color_list = cm.gnuplot(np.linspace(0, 1, 16))
+        p = df.A.plot.bar(figsize=(16, 7), color=color_list)
+        assert p.patches[1].get_facecolor() == p.patches[17].get_facecolor()
+
+    def test_dictionary_color(self):
+        # issue-8193
+        # Test plot color dictionary format
+        data_files = ["a", "b"]
+
+        expected = [(0.5, 0.24, 0.6), (0.3, 0.7, 0.7)]
+
+        df1 = DataFrame(np.random.rand(2, 2), columns=data_files)
+        dic_color = {"b": (0.3, 0.7, 0.7), "a": (0.5, 0.24, 0.6)}
+
+        # Bar color test
+        ax = df1.plot(kind="bar", color=dic_color)
+        colors = [rect.get_facecolor()[0:-1] for rect in ax.get_children()[0:3:2]]
+        assert all(color == expected[index] for index, color in enumerate(colors))
+
+        # Line color test
+        ax = df1.plot(kind="line", color=dic_color)
+        colors = [rect.get_color() for rect in ax.get_lines()[0:2]]
+        assert all(color == expected[index] for index, color in enumerate(colors))
+
+    def test_has_externally_shared_axis_x_axis(self):
+        # GH33819
+        # Test _has_externally_shared_axis() works for x-axis
+        func = plotting._matplotlib.tools._has_externally_shared_axis
+
+        fig = self.plt.figure()
+        plots = fig.subplots(2, 4)
+
+        # Create *externally* shared axes for first and third columns
+        plots[0][0] = fig.add_subplot(231, sharex=plots[1][0])
+        plots[0][2] = fig.add_subplot(233, sharex=plots[1][2])
+
+        # Create *internally* shared axes for second and third columns
+        plots[0][1].twinx()
+        plots[0][2].twinx()
+
+        # First  column is only externally shared
+        # Second column is only internally shared
+        # Third  column is both
+        # Fourth column is neither
+        assert func(plots[0][0], "x")
+        assert not func(plots[0][1], "x")
+        assert func(plots[0][2], "x")
+        assert not func(plots[0][3], "x")
+
+    def test_has_externally_shared_axis_y_axis(self):
+        # GH33819
+        # Test _has_externally_shared_axis() works for y-axis
+        func = plotting._matplotlib.tools._has_externally_shared_axis
+
+        fig = self.plt.figure()
+        plots = fig.subplots(4, 2)
+
+        # Create *externally* shared axes for first and third rows
+        plots[0][0] = fig.add_subplot(321, sharey=plots[0][1])
+        plots[2][0] = fig.add_subplot(325, sharey=plots[2][1])
+
+        # Create *internally* shared axes for second and third rows
+        plots[1][0].twiny()
+        plots[2][0].twiny()
+
+        # First  row is only externally shared
+        # Second row is only internally shared
+        # Third  row is both
+        # Fourth row is neither
+        assert func(plots[0][0], "y")
+        assert not func(plots[1][0], "y")
+        assert func(plots[2][0], "y")
+        assert not func(plots[3][0], "y")
+
+    def test_has_externally_shared_axis_invalid_compare_axis(self):
+        # GH33819
+        # Test _has_externally_shared_axis() raises an exception when
+        # passed an invalid value as compare_axis parameter
+        func = plotting._matplotlib.tools._has_externally_shared_axis
+
+        fig = self.plt.figure()
+        plots = fig.subplots(4, 2)
+
+        # Create arbitrary axes
+        plots[0][0] = fig.add_subplot(321, sharey=plots[0][1])
+
+        # Check that an invalid compare_axis value triggers the expected exception
+        msg = "needs 'x' or 'y' as a second parameter"
+        with pytest.raises(ValueError, match=msg):
+            func(plots[0][0], "z")
+
+    def test_externally_shared_axes(self):
+        # Example from GH33819
+        # Create data
+        df = DataFrame({"a": np.random.randn(1000), "b": np.random.randn(1000)})
+
+        # Create figure
+        fig = self.plt.figure()
+        plots = fig.subplots(2, 3)
+
+        # Create *externally* shared axes
+        plots[0][0] = fig.add_subplot(231, sharex=plots[1][0])
+        # note: no plots[0][1] that's the twin only case
+        plots[0][2] = fig.add_subplot(233, sharex=plots[1][2])
+
+        # Create *internally* shared axes
+        # note: no plots[0][0] that's the external only case
+        twin_ax1 = plots[0][1].twinx()
+        twin_ax2 = plots[0][2].twinx()
+
+        # Plot data to primary axes
+        df["a"].plot(ax=plots[0][0], title="External share only").set_xlabel(
+            "this label should never be visible"
+        )
+        df["a"].plot(ax=plots[1][0])
+
+        df["a"].plot(ax=plots[0][1], title="Internal share (twin) only").set_xlabel(
+            "this label should always be visible"
+        )
+        df["a"].plot(ax=plots[1][1])
+
+        df["a"].plot(ax=plots[0][2], title="Both").set_xlabel(
+            "this label should never be visible"
+        )
+        df["a"].plot(ax=plots[1][2])
+
+        # Plot data to twinned axes
+        df["b"].plot(ax=twin_ax1, color="green")
+        df["b"].plot(ax=twin_ax2, color="yellow")
+
+        assert not plots[0][0].xaxis.get_label().get_visible()
+        assert plots[0][1].xaxis.get_label().get_visible()
+        assert not plots[0][2].xaxis.get_label().get_visible()

.venv/Lib/site-packages/pandas/tests/plotting/test_series.py

@@ -0,0 +1,817 @@
+""" Test cases for Series.plot """
+
+
+from datetime import datetime
+from itertools import chain
+
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+import pandas as pd
+from pandas import (
+    DataFrame,
+    Series,
+    date_range,
+)
+import pandas._testing as tm
+from pandas.tests.plotting.common import (
+    TestPlotBase,
+    _check_plot_works,
+)
+
+import pandas.plotting as plotting
+
+pytestmark = pytest.mark.slow
+
+
+@td.skip_if_no_mpl
+class TestSeriesPlots(TestPlotBase):
+    def setup_method(self, method):
+        TestPlotBase.setup_method(self, method)
+        import matplotlib as mpl
+
+        mpl.rcdefaults()
+
+        self.ts = tm.makeTimeSeries()
+        self.ts.name = "ts"
+
+        self.series = tm.makeStringSeries()
+        self.series.name = "series"
+
+        self.iseries = tm.makePeriodSeries()
+        self.iseries.name = "iseries"
+
+    def test_plot(self):
+        _check_plot_works(self.ts.plot, label="foo")
+        _check_plot_works(self.ts.plot, use_index=False)
+        axes = _check_plot_works(self.ts.plot, rot=0)
+        self._check_ticks_props(axes, xrot=0)
+
+        ax = _check_plot_works(self.ts.plot, style=".", logy=True)
+        self._check_ax_scales(ax, yaxis="log")
+
+        ax = _check_plot_works(self.ts.plot, style=".", logx=True)
+        self._check_ax_scales(ax, xaxis="log")
+
+        ax = _check_plot_works(self.ts.plot, style=".", loglog=True)
+        self._check_ax_scales(ax, xaxis="log", yaxis="log")
+
+        _check_plot_works(self.ts[:10].plot.bar)
+        _check_plot_works(self.ts.plot.area, stacked=False)
+        _check_plot_works(self.iseries.plot)
+
+        for kind in ["line", "bar", "barh", "kde", "hist", "box"]:
+            _check_plot_works(self.series[:5].plot, kind=kind)
+
+        _check_plot_works(self.series[:10].plot.barh)
+        ax = _check_plot_works(Series(np.random.randn(10)).plot.bar, color="black")
+        self._check_colors([ax.patches[0]], facecolors=["black"])
+
+        # GH 6951
+        ax = _check_plot_works(self.ts.plot, subplots=True)
+        self._check_axes_shape(ax, axes_num=1, layout=(1, 1))
+
+        ax = _check_plot_works(self.ts.plot, subplots=True, layout=(-1, 1))
+        self._check_axes_shape(ax, axes_num=1, layout=(1, 1))
+        ax = _check_plot_works(self.ts.plot, subplots=True, layout=(1, -1))
+        self._check_axes_shape(ax, axes_num=1, layout=(1, 1))
+
+    def test_plot_figsize_and_title(self):
+        # figsize and title
+        _, ax = self.plt.subplots()
+        ax = self.series.plot(title="Test", figsize=(16, 8), ax=ax)
+        self._check_text_labels(ax.title, "Test")
+        self._check_axes_shape(ax, axes_num=1, layout=(1, 1), figsize=(16, 8))
+
+    def test_dont_modify_rcParams(self):
+        # GH 8242
+        key = "axes.prop_cycle"
+        colors = self.plt.rcParams[key]
+        _, ax = self.plt.subplots()
+        Series([1, 2, 3]).plot(ax=ax)
+        assert colors == self.plt.rcParams[key]
+
+    def test_ts_line_lim(self):
+        fig, ax = self.plt.subplots()
+        ax = self.ts.plot(ax=ax)
+        xmin, xmax = ax.get_xlim()
+        lines = ax.get_lines()
+        assert xmin <= lines[0].get_data(orig=False)[0][0]
+        assert xmax >= lines[0].get_data(orig=False)[0][-1]
+        tm.close()
+
+        ax = self.ts.plot(secondary_y=True, ax=ax)
+        xmin, xmax = ax.get_xlim()
+        lines = ax.get_lines()
+        assert xmin <= lines[0].get_data(orig=False)[0][0]
+        assert xmax >= lines[0].get_data(orig=False)[0][-1]
+
+    def test_ts_area_lim(self):
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.area(stacked=False, ax=ax)
+        xmin, xmax = ax.get_xlim()
+        line = ax.get_lines()[0].get_data(orig=False)[0]
+        assert xmin <= line[0]
+        assert xmax >= line[-1]
+        self._check_ticks_props(ax, xrot=0)
+        tm.close()
+
+        # GH 7471
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.area(stacked=False, x_compat=True, ax=ax)
+        xmin, xmax = ax.get_xlim()
+        line = ax.get_lines()[0].get_data(orig=False)[0]
+        assert xmin <= line[0]
+        assert xmax >= line[-1]
+        self._check_ticks_props(ax, xrot=30)
+        tm.close()
+
+        tz_ts = self.ts.copy()
+        tz_ts.index = tz_ts.tz_localize("GMT").tz_convert("CET")
+        _, ax = self.plt.subplots()
+        ax = tz_ts.plot.area(stacked=False, x_compat=True, ax=ax)
+        xmin, xmax = ax.get_xlim()
+        line = ax.get_lines()[0].get_data(orig=False)[0]
+        assert xmin <= line[0]
+        assert xmax >= line[-1]
+        self._check_ticks_props(ax, xrot=0)
+        tm.close()
+
+        _, ax = self.plt.subplots()
+        ax = tz_ts.plot.area(stacked=False, secondary_y=True, ax=ax)
+        xmin, xmax = ax.get_xlim()
+        line = ax.get_lines()[0].get_data(orig=False)[0]
+        assert xmin <= line[0]
+        assert xmax >= line[-1]
+        self._check_ticks_props(ax, xrot=0)
+
+    def test_area_sharey_dont_overwrite(self):
+        # GH37942
+        fig, (ax1, ax2) = self.plt.subplots(1, 2, sharey=True)
+
+        abs(self.ts).plot(ax=ax1, kind="area")
+        abs(self.ts).plot(ax=ax2, kind="area")
+
+        assert self.get_y_axis(ax1).joined(ax1, ax2)
+        assert self.get_y_axis(ax2).joined(ax1, ax2)
+
+    def test_label(self):
+        s = Series([1, 2])
+        _, ax = self.plt.subplots()
+        ax = s.plot(label="LABEL", legend=True, ax=ax)
+        self._check_legend_labels(ax, labels=["LABEL"])
+        self.plt.close()
+        _, ax = self.plt.subplots()
+        ax = s.plot(legend=True, ax=ax)
+        self._check_legend_labels(ax, labels=["None"])
+        self.plt.close()
+        # get name from index
+        s.name = "NAME"
+        _, ax = self.plt.subplots()
+        ax = s.plot(legend=True, ax=ax)
+        self._check_legend_labels(ax, labels=["NAME"])
+        self.plt.close()
+        # override the default
+        _, ax = self.plt.subplots()
+        ax = s.plot(legend=True, label="LABEL", ax=ax)
+        self._check_legend_labels(ax, labels=["LABEL"])
+        self.plt.close()
+        # Add lebel info, but don't draw
+        _, ax = self.plt.subplots()
+        ax = s.plot(legend=False, label="LABEL", ax=ax)
+        assert ax.get_legend() is None  # Hasn't been drawn
+        ax.legend()  # draw it
+        self._check_legend_labels(ax, labels=["LABEL"])
+
+    def test_boolean(self):
+        # GH 23719
+        s = Series([False, False, True])
+        _check_plot_works(s.plot, include_bool=True)
+
+        msg = "no numeric data to plot"
+        with pytest.raises(TypeError, match=msg):
+            _check_plot_works(s.plot)
+
+    def test_line_area_nan_series(self):
+        values = [1, 2, np.nan, 3]
+        s = Series(values)
+        ts = Series(values, index=tm.makeDateIndex(k=4))
+
+        for d in [s, ts]:
+            ax = _check_plot_works(d.plot)
+            masked = ax.lines[0].get_ydata()
+            # remove nan for comparison purpose
+            exp = np.array([1, 2, 3], dtype=np.float64)
+            tm.assert_numpy_array_equal(np.delete(masked.data, 2), exp)
+            tm.assert_numpy_array_equal(
+                masked.mask, np.array([False, False, True, False])
+            )
+
+            expected = np.array([1, 2, 0, 3], dtype=np.float64)
+            ax = _check_plot_works(d.plot, stacked=True)
+            tm.assert_numpy_array_equal(ax.lines[0].get_ydata(), expected)
+            ax = _check_plot_works(d.plot.area)
+            tm.assert_numpy_array_equal(ax.lines[0].get_ydata(), expected)
+            ax = _check_plot_works(d.plot.area, stacked=False)
+            tm.assert_numpy_array_equal(ax.lines[0].get_ydata(), expected)
+
+    def test_line_use_index_false(self):
+        s = Series([1, 2, 3], index=["a", "b", "c"])
+        s.index.name = "The Index"
+        _, ax = self.plt.subplots()
+        ax = s.plot(use_index=False, ax=ax)
+        label = ax.get_xlabel()
+        assert label == ""
+        _, ax = self.plt.subplots()
+        ax2 = s.plot.bar(use_index=False, ax=ax)
+        label2 = ax2.get_xlabel()
+        assert label2 == ""
+
+    def test_bar_log(self):
+        expected = np.array([1e-1, 1e0, 1e1, 1e2, 1e3, 1e4])
+
+        _, ax = self.plt.subplots()
+        ax = Series([200, 500]).plot.bar(log=True, ax=ax)
+        tm.assert_numpy_array_equal(ax.yaxis.get_ticklocs(), expected)
+        tm.close()
+
+        _, ax = self.plt.subplots()
+        ax = Series([200, 500]).plot.barh(log=True, ax=ax)
+        tm.assert_numpy_array_equal(ax.xaxis.get_ticklocs(), expected)
+        tm.close()
+
+        # GH 9905
+        expected = np.array([1e-5, 1e-4, 1e-3, 1e-2, 1e-1, 1e0, 1e1])
+
+        _, ax = self.plt.subplots()
+        ax = Series([0.1, 0.01, 0.001]).plot(log=True, kind="bar", ax=ax)
+        ymin = 0.0007943282347242822
+        ymax = 0.12589254117941673
+        res = ax.get_ylim()
+        tm.assert_almost_equal(res[0], ymin)
+        tm.assert_almost_equal(res[1], ymax)
+        tm.assert_numpy_array_equal(ax.yaxis.get_ticklocs(), expected)
+        tm.close()
+
+        _, ax = self.plt.subplots()
+        ax = Series([0.1, 0.01, 0.001]).plot(log=True, kind="barh", ax=ax)
+        res = ax.get_xlim()
+        tm.assert_almost_equal(res[0], ymin)
+        tm.assert_almost_equal(res[1], ymax)
+        tm.assert_numpy_array_equal(ax.xaxis.get_ticklocs(), expected)
+
+    def test_bar_ignore_index(self):
+        df = Series([1, 2, 3, 4], index=["a", "b", "c", "d"])
+        _, ax = self.plt.subplots()
+        ax = df.plot.bar(use_index=False, ax=ax)
+        self._check_text_labels(ax.get_xticklabels(), ["0", "1", "2", "3"])
+
+    def test_bar_user_colors(self):
+        s = Series([1, 2, 3, 4])
+        ax = s.plot.bar(color=["red", "blue", "blue", "red"])
+        result = [p.get_facecolor() for p in ax.patches]
+        expected = [
+            (1.0, 0.0, 0.0, 1.0),
+            (0.0, 0.0, 1.0, 1.0),
+            (0.0, 0.0, 1.0, 1.0),
+            (1.0, 0.0, 0.0, 1.0),
+        ]
+        assert result == expected
+
+    def test_rotation(self):
+        df = DataFrame(np.random.randn(5, 5))
+        # Default rot 0
+        _, ax = self.plt.subplots()
+        axes = df.plot(ax=ax)
+        self._check_ticks_props(axes, xrot=0)
+
+        _, ax = self.plt.subplots()
+        axes = df.plot(rot=30, ax=ax)
+        self._check_ticks_props(axes, xrot=30)
+
+    def test_irregular_datetime(self):
+        from pandas.plotting._matplotlib.converter import DatetimeConverter
+
+        rng = date_range("1/1/2000", "3/1/2000")
+        rng = rng[[0, 1, 2, 3, 5, 9, 10, 11, 12]]
+        ser = Series(np.random.randn(len(rng)), rng)
+        _, ax = self.plt.subplots()
+        ax = ser.plot(ax=ax)
+        xp = DatetimeConverter.convert(datetime(1999, 1, 1), "", ax)
+        ax.set_xlim("1/1/1999", "1/1/2001")
+        assert xp == ax.get_xlim()[0]
+        self._check_ticks_props(ax, xrot=30)
+
+    def test_unsorted_index_xlim(self):
+        ser = Series(
+            [0.0, 1.0, np.nan, 3.0, 4.0, 5.0, 6.0],
+            index=[1.0, 0.0, 3.0, 2.0, np.nan, 3.0, 2.0],
+        )
+        _, ax = self.plt.subplots()
+        ax = ser.plot(ax=ax)
+        xmin, xmax = ax.get_xlim()
+        lines = ax.get_lines()
+        assert xmin <= np.nanmin(lines[0].get_data(orig=False)[0])
+        assert xmax >= np.nanmax(lines[0].get_data(orig=False)[0])
+
+    def test_pie_series(self):
+        # if sum of values is less than 1.0, pie handle them as rate and draw
+        # semicircle.
+        series = Series(
+            np.random.randint(1, 5), index=["a", "b", "c", "d", "e"], name="YLABEL"
+        )
+        ax = _check_plot_works(series.plot.pie)
+        self._check_text_labels(ax.texts, series.index)
+        assert ax.get_ylabel() == "YLABEL"
+
+        # without wedge labels
+        ax = _check_plot_works(series.plot.pie, labels=None)
+        self._check_text_labels(ax.texts, [""] * 5)
+
+        # with less colors than elements
+        color_args = ["r", "g", "b"]
+        ax = _check_plot_works(series.plot.pie, colors=color_args)
+
+        color_expected = ["r", "g", "b", "r", "g"]
+        self._check_colors(ax.patches, facecolors=color_expected)
+
+        # with labels and colors
+        labels = ["A", "B", "C", "D", "E"]
+        color_args = ["r", "g", "b", "c", "m"]
+        ax = _check_plot_works(series.plot.pie, labels=labels, colors=color_args)
+        self._check_text_labels(ax.texts, labels)
+        self._check_colors(ax.patches, facecolors=color_args)
+
+        # with autopct and fontsize
+        ax = _check_plot_works(
+            series.plot.pie, colors=color_args, autopct="%.2f", fontsize=7
+        )
+        pcts = [f"{s*100:.2f}" for s in series.values / series.sum()]
+        expected_texts = list(chain.from_iterable(zip(series.index, pcts)))
+        self._check_text_labels(ax.texts, expected_texts)
+        for t in ax.texts:
+            assert t.get_fontsize() == 7
+
+        # includes negative value
+        series = Series([1, 2, 0, 4, -1], index=["a", "b", "c", "d", "e"])
+        with pytest.raises(ValueError, match="pie plot doesn't allow negative values"):
+            series.plot.pie()
+
+        # includes nan
+        series = Series([1, 2, np.nan, 4], index=["a", "b", "c", "d"], name="YLABEL")
+        ax = _check_plot_works(series.plot.pie)
+        self._check_text_labels(ax.texts, ["a", "b", "", "d"])
+
+    def test_pie_nan(self):
+        s = Series([1, np.nan, 1, 1])
+        _, ax = self.plt.subplots()
+        ax = s.plot.pie(legend=True, ax=ax)
+        expected = ["0", "", "2", "3"]
+        result = [x.get_text() for x in ax.texts]
+        assert result == expected
+
+    def test_df_series_secondary_legend(self):
+        # GH 9779
+        df = DataFrame(np.random.randn(30, 3), columns=list("abc"))
+        s = Series(np.random.randn(30), name="x")
+
+        # primary -> secondary (without passing ax)
+        _, ax = self.plt.subplots()
+        ax = df.plot(ax=ax)
+        s.plot(legend=True, secondary_y=True, ax=ax)
+        # both legends are drawn on left ax
+        # left and right axis must be visible
+        self._check_legend_labels(ax, labels=["a", "b", "c", "x (right)"])
+        assert ax.get_yaxis().get_visible()
+        assert ax.right_ax.get_yaxis().get_visible()
+        tm.close()
+
+        # primary -> secondary (with passing ax)
+        _, ax = self.plt.subplots()
+        ax = df.plot(ax=ax)
+        s.plot(ax=ax, legend=True, secondary_y=True)
+        # both legends are drawn on left ax
+        # left and right axis must be visible
+        self._check_legend_labels(ax, labels=["a", "b", "c", "x (right)"])
+        assert ax.get_yaxis().get_visible()
+        assert ax.right_ax.get_yaxis().get_visible()
+        tm.close()
+
+        # secondary -> secondary (without passing ax)
+        _, ax = self.plt.subplots()
+        ax = df.plot(secondary_y=True, ax=ax)
+        s.plot(legend=True, secondary_y=True, ax=ax)
+        # both legends are drawn on left ax
+        # left axis must be invisible and right axis must be visible
+        expected = ["a (right)", "b (right)", "c (right)", "x (right)"]
+        self._check_legend_labels(ax.left_ax, labels=expected)
+        assert not ax.left_ax.get_yaxis().get_visible()
+        assert ax.get_yaxis().get_visible()
+        tm.close()
+
+        # secondary -> secondary (with passing ax)
+        _, ax = self.plt.subplots()
+        ax = df.plot(secondary_y=True, ax=ax)
+        s.plot(ax=ax, legend=True, secondary_y=True)
+        # both legends are drawn on left ax
+        # left axis must be invisible and right axis must be visible
+        expected = ["a (right)", "b (right)", "c (right)", "x (right)"]
+        self._check_legend_labels(ax.left_ax, expected)
+        assert not ax.left_ax.get_yaxis().get_visible()
+        assert ax.get_yaxis().get_visible()
+        tm.close()
+
+        # secondary -> secondary (with passing ax)
+        _, ax = self.plt.subplots()
+        ax = df.plot(secondary_y=True, mark_right=False, ax=ax)
+        s.plot(ax=ax, legend=True, secondary_y=True)
+        # both legends are drawn on left ax
+        # left axis must be invisible and right axis must be visible
+        expected = ["a", "b", "c", "x (right)"]
+        self._check_legend_labels(ax.left_ax, expected)
+        assert not ax.left_ax.get_yaxis().get_visible()
+        assert ax.get_yaxis().get_visible()
+        tm.close()
+
+    @pytest.mark.parametrize(
+        "input_logy, expected_scale", [(True, "log"), ("sym", "symlog")]
+    )
+    def test_secondary_logy(self, input_logy, expected_scale):
+        # GH 25545
+        s1 = Series(np.random.randn(30))
+        s2 = Series(np.random.randn(30))
+
+        # GH 24980
+        ax1 = s1.plot(logy=input_logy)
+        ax2 = s2.plot(secondary_y=True, logy=input_logy)
+
+        assert ax1.get_yscale() == expected_scale
+        assert ax2.get_yscale() == expected_scale
+
+    def test_plot_fails_with_dupe_color_and_style(self):
+        x = Series(np.random.randn(2))
+        _, ax = self.plt.subplots()
+        msg = (
+            "Cannot pass 'style' string with a color symbol and 'color' keyword "
+            "argument. Please use one or the other or pass 'style' without a color "
+            "symbol"
+        )
+        with pytest.raises(ValueError, match=msg):
+            x.plot(style="k--", color="k", ax=ax)
+
+    @td.skip_if_no_scipy
+    def test_kde_kwargs(self):
+        sample_points = np.linspace(-100, 100, 20)
+        _check_plot_works(self.ts.plot.kde, bw_method="scott", ind=20)
+        _check_plot_works(self.ts.plot.kde, bw_method=None, ind=20)
+        _check_plot_works(self.ts.plot.kde, bw_method=None, ind=np.int_(20))
+        _check_plot_works(self.ts.plot.kde, bw_method=0.5, ind=sample_points)
+        _check_plot_works(self.ts.plot.density, bw_method=0.5, ind=sample_points)
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.kde(logy=True, bw_method=0.5, ind=sample_points, ax=ax)
+        self._check_ax_scales(ax, yaxis="log")
+        self._check_text_labels(ax.yaxis.get_label(), "Density")
+
+    @td.skip_if_no_scipy
+    def test_kde_missing_vals(self):
+        s = Series(np.random.uniform(size=50))
+        s[0] = np.nan
+        axes = _check_plot_works(s.plot.kde)
+
+        # gh-14821: check if the values have any missing values
+        assert any(~np.isnan(axes.lines[0].get_xdata()))
+
+    def test_boxplot_series(self):
+        _, ax = self.plt.subplots()
+        ax = self.ts.plot.box(logy=True, ax=ax)
+        self._check_ax_scales(ax, yaxis="log")
+        xlabels = ax.get_xticklabels()
+        self._check_text_labels(xlabels, [self.ts.name])
+        ylabels = ax.get_yticklabels()
+        self._check_text_labels(ylabels, [""] * len(ylabels))
+
+    def test_kind_both_ways(self):
+        s = Series(range(3))
+        kinds = (
+            plotting.PlotAccessor._common_kinds + plotting.PlotAccessor._series_kinds
+        )
+        for kind in kinds:
+            _, ax = self.plt.subplots()
+            s.plot(kind=kind, ax=ax)
+            self.plt.close()
+            _, ax = self.plt.subplots()
+            getattr(s.plot, kind)()
+            self.plt.close()
+
+    def test_invalid_plot_data(self):
+        s = Series(list("abcd"))
+        _, ax = self.plt.subplots()
+        for kind in plotting.PlotAccessor._common_kinds:
+
+            msg = "no numeric data to plot"
+            with pytest.raises(TypeError, match=msg):
+                s.plot(kind=kind, ax=ax)
+
+    def test_valid_object_plot(self):
+        s = Series(range(10), dtype=object)
+        for kind in plotting.PlotAccessor._common_kinds:
+            _check_plot_works(s.plot, kind=kind)
+
+    def test_partially_invalid_plot_data(self):
+        s = Series(["a", "b", 1.0, 2])
+        _, ax = self.plt.subplots()
+        for kind in plotting.PlotAccessor._common_kinds:
+
+            msg = "no numeric data to plot"
+            with pytest.raises(TypeError, match=msg):
+                s.plot(kind=kind, ax=ax)
+
+    def test_invalid_kind(self):
+        s = Series([1, 2])
+        with pytest.raises(ValueError, match="invalid_kind is not a valid plot kind"):
+            s.plot(kind="invalid_kind")
+
+    def test_dup_datetime_index_plot(self):
+        dr1 = date_range("1/1/2009", periods=4)
+        dr2 = date_range("1/2/2009", periods=4)
+        index = dr1.append(dr2)
+        values = np.random.randn(index.size)
+        s = Series(values, index=index)
+        _check_plot_works(s.plot)
+
+    def test_errorbar_asymmetrical(self):
+        # GH9536
+        s = Series(np.arange(10), name="x")
+        err = np.random.rand(2, 10)
+
+        ax = s.plot(yerr=err, xerr=err)
+
+        result = np.vstack([i.vertices[:, 1] for i in ax.collections[1].get_paths()])
+        expected = (err.T * np.array([-1, 1])) + s.to_numpy().reshape(-1, 1)
+        tm.assert_numpy_array_equal(result, expected)
+
+        msg = (
+            "Asymmetrical error bars should be provided "
+            f"with the shape \\(2, {len(s)}\\)"
+        )
+        with pytest.raises(ValueError, match=msg):
+            s.plot(yerr=np.random.rand(2, 11))
+
+        tm.close()
+
+    def test_errorbar_plot(self):
+
+        s = Series(np.arange(10), name="x")
+        s_err = np.random.randn(10)
+        d_err = DataFrame(np.random.randn(10, 2), index=s.index, columns=["x", "y"])
+        # test line and bar plots
+        kinds = ["line", "bar"]
+        for kind in kinds:
+            ax = _check_plot_works(s.plot, yerr=Series(s_err), kind=kind)
+            self._check_has_errorbars(ax, xerr=0, yerr=1)
+            ax = _check_plot_works(s.plot, yerr=s_err, kind=kind)
+            self._check_has_errorbars(ax, xerr=0, yerr=1)
+            ax = _check_plot_works(s.plot, yerr=s_err.tolist(), kind=kind)
+            self._check_has_errorbars(ax, xerr=0, yerr=1)
+            ax = _check_plot_works(s.plot, yerr=d_err, kind=kind)
+            self._check_has_errorbars(ax, xerr=0, yerr=1)
+            ax = _check_plot_works(s.plot, xerr=0.2, yerr=0.2, kind=kind)
+            self._check_has_errorbars(ax, xerr=1, yerr=1)
+
+        ax = _check_plot_works(s.plot, xerr=s_err)
+        self._check_has_errorbars(ax, xerr=1, yerr=0)
+
+        # test time series plotting
+        ix = date_range("1/1/2000", "1/1/2001", freq="M")
+        ts = Series(np.arange(12), index=ix, name="x")
+        ts_err = Series(np.random.randn(12), index=ix)
+        td_err = DataFrame(np.random.randn(12, 2), index=ix, columns=["x", "y"])
+
+        ax = _check_plot_works(ts.plot, yerr=ts_err)
+        self._check_has_errorbars(ax, xerr=0, yerr=1)
+        ax = _check_plot_works(ts.plot, yerr=td_err)
+        self._check_has_errorbars(ax, xerr=0, yerr=1)
+
+        # check incorrect lengths and types
+        with tm.external_error_raised(ValueError):
+            s.plot(yerr=np.arange(11))
+
+        s_err = ["zzz"] * 10
+        with tm.external_error_raised(TypeError):
+            s.plot(yerr=s_err)
+
+    def test_table(self):
+        _check_plot_works(self.series.plot, table=True)
+        _check_plot_works(self.series.plot, table=self.series)
+
+    def test_series_grid_settings(self):
+        # Make sure plot defaults to rcParams['axes.grid'] setting, GH 9792
+        self._check_grid_settings(
+            Series([1, 2, 3]),
+            plotting.PlotAccessor._series_kinds + plotting.PlotAccessor._common_kinds,
+        )
+
+    def test_standard_colors(self):
+        from pandas.plotting._matplotlib.style import get_standard_colors
+
+        for c in ["r", "red", "green", "#FF0000"]:
+            result = get_standard_colors(1, color=c)
+            assert result == [c]
+
+            result = get_standard_colors(1, color=[c])
+            assert result == [c]
+
+            result = get_standard_colors(3, color=c)
+            assert result == [c] * 3
+
+            result = get_standard_colors(3, color=[c])
+            assert result == [c] * 3
+
+    def test_standard_colors_all(self):
+        import matplotlib.colors as colors
+
+        from pandas.plotting._matplotlib.style import get_standard_colors
+
+        # multiple colors like mediumaquamarine
+        for c in colors.cnames:
+            result = get_standard_colors(num_colors=1, color=c)
+            assert result == [c]
+
+            result = get_standard_colors(num_colors=1, color=[c])
+            assert result == [c]
+
+            result = get_standard_colors(num_colors=3, color=c)
+            assert result == [c] * 3
+
+            result = get_standard_colors(num_colors=3, color=[c])
+            assert result == [c] * 3
+
+        # single letter colors like k
+        for c in colors.ColorConverter.colors:
+            result = get_standard_colors(num_colors=1, color=c)
+            assert result == [c]
+
+            result = get_standard_colors(num_colors=1, color=[c])
+            assert result == [c]
+
+            result = get_standard_colors(num_colors=3, color=c)
+            assert result == [c] * 3
+
+            result = get_standard_colors(num_colors=3, color=[c])
+            assert result == [c] * 3
+
+    def test_series_plot_color_kwargs(self):
+        # GH1890
+        _, ax = self.plt.subplots()
+        ax = Series(np.arange(12) + 1).plot(color="green", ax=ax)
+        self._check_colors(ax.get_lines(), linecolors=["green"])
+
+    def test_time_series_plot_color_kwargs(self):
+        # #1890
+        _, ax = self.plt.subplots()
+        ax = Series(np.arange(12) + 1, index=date_range("1/1/2000", periods=12)).plot(
+            color="green", ax=ax
+        )
+        self._check_colors(ax.get_lines(), linecolors=["green"])
+
+    def test_time_series_plot_color_with_empty_kwargs(self):
+        import matplotlib as mpl
+
+        def_colors = self._unpack_cycler(mpl.rcParams)
+        index = date_range("1/1/2000", periods=12)
+        s = Series(np.arange(1, 13), index=index)
+
+        ncolors = 3
+
+        _, ax = self.plt.subplots()
+        for i in range(ncolors):
+            ax = s.plot(ax=ax)
+        self._check_colors(ax.get_lines(), linecolors=def_colors[:ncolors])
+
+    def test_xticklabels(self):
+        # GH11529
+        s = Series(np.arange(10), index=[f"P{i:02d}" for i in range(10)])
+        _, ax = self.plt.subplots()
+        ax = s.plot(xticks=[0, 3, 5, 9], ax=ax)
+        exp = [f"P{i:02d}" for i in [0, 3, 5, 9]]
+        self._check_text_labels(ax.get_xticklabels(), exp)
+
+    def test_xtick_barPlot(self):
+        # GH28172
+        s = Series(range(10), index=[f"P{i:02d}" for i in range(10)])
+        ax = s.plot.bar(xticks=range(0, 11, 2))
+        exp = np.array(list(range(0, 11, 2)))
+        tm.assert_numpy_array_equal(exp, ax.get_xticks())
+
+    def test_custom_business_day_freq(self):
+        # GH7222
+        from pandas.tseries.offsets import CustomBusinessDay
+
+        s = Series(
+            range(100, 121),
+            index=pd.bdate_range(
+                start="2014-05-01",
+                end="2014-06-01",
+                freq=CustomBusinessDay(holidays=["2014-05-26"]),
+            ),
+        )
+
+        _check_plot_works(s.plot)
+
+    @pytest.mark.xfail(reason="GH#24426")
+    def test_plot_accessor_updates_on_inplace(self):
+        ser = Series([1, 2, 3, 4])
+        _, ax = self.plt.subplots()
+        ax = ser.plot(ax=ax)
+        before = ax.xaxis.get_ticklocs()
+
+        ser.drop([0, 1], inplace=True)
+        _, ax = self.plt.subplots()
+        after = ax.xaxis.get_ticklocs()
+        tm.assert_numpy_array_equal(before, after)
+
+    @pytest.mark.parametrize("kind", ["line", "area"])
+    def test_plot_xlim_for_series(self, kind):
+        # test if xlim is also correctly plotted in Series for line and area
+        # GH 27686
+        s = Series([2, 3])
+        _, ax = self.plt.subplots()
+        s.plot(kind=kind, ax=ax)
+        xlims = ax.get_xlim()
+
+        assert xlims[0] < 0
+        assert xlims[1] > 1
+
+    def test_plot_no_rows(self):
+        # GH 27758
+        df = Series(dtype=int)
+        assert df.empty
+        ax = df.plot()
+        assert len(ax.get_lines()) == 1
+        line = ax.get_lines()[0]
+        assert len(line.get_xdata()) == 0
+        assert len(line.get_ydata()) == 0
+
+    def test_plot_no_numeric_data(self):
+        df = Series(["a", "b", "c"])
+        with pytest.raises(TypeError, match="no numeric data to plot"):
+            df.plot()
+
+    @pytest.mark.parametrize(
+        "data, index",
+        [
+            ([1, 2, 3, 4], [3, 2, 1, 0]),
+            ([10, 50, 20, 30], [1910, 1920, 1980, 1950]),
+        ],
+    )
+    def test_plot_order(self, data, index):
+        # GH38865 Verify plot order of a Series
+        ser = Series(data=data, index=index)
+        ax = ser.plot(kind="bar")
+
+        expected = ser.tolist()
+        result = [
+            patch.get_bbox().ymax
+            for patch in sorted(ax.patches, key=lambda patch: patch.get_bbox().xmax)
+        ]
+        assert expected == result
+
+    def test_style_single_ok(self):
+        s = Series([1, 2])
+        ax = s.plot(style="s", color="C3")
+        assert ax.lines[0].get_color() == "C3"
+
+    @pytest.mark.parametrize(
+        "index_name, old_label, new_label",
+        [(None, "", "new"), ("old", "old", "new"), (None, "", "")],
+    )
+    @pytest.mark.parametrize("kind", ["line", "area", "bar"])
+    def test_xlabel_ylabel_series(self, kind, index_name, old_label, new_label):
+        # GH 9093
+        ser = Series([1, 2, 3, 4])
+        ser.index.name = index_name
+
+        # default is the ylabel is not shown and xlabel is index name
+        ax = ser.plot(kind=kind)
+        assert ax.get_ylabel() == ""
+        assert ax.get_xlabel() == old_label
+
+        # old xlabel will be overridden and assigned ylabel will be used as ylabel
+        ax = ser.plot(kind=kind, ylabel=new_label, xlabel=new_label)
+        assert ax.get_ylabel() == new_label
+        assert ax.get_xlabel() == new_label
+
+    @pytest.mark.parametrize(
+        "index",
+        [
+            pd.timedelta_range(start=0, periods=2, freq="D"),
+            [pd.Timedelta(days=1), pd.Timedelta(days=2)],
+        ],
+    )
+    def test_timedelta_index(self, index):
+        # GH37454
+        xlims = (3, 1)
+        ax = Series([1, 2], index=index).plot(xlim=(xlims))
+        assert ax.get_xlim() == (3, 1)

.venv/Lib/site-packages/pandas/tests/plotting/test_style.py

@@ -0,0 +1,159 @@
+import pytest
+
+from pandas import Series
+
+pytest.importorskip("matplotlib")
+from pandas.plotting._matplotlib.style import get_standard_colors
+
+pytestmark = pytest.mark.slow
+
+
+class TestGetStandardColors:
+    @pytest.mark.parametrize(
+        "num_colors, expected",
+        [
+            (3, ["red", "green", "blue"]),
+            (5, ["red", "green", "blue", "red", "green"]),
+            (7, ["red", "green", "blue", "red", "green", "blue", "red"]),
+            (2, ["red", "green"]),
+            (1, ["red"]),
+        ],
+    )
+    def test_default_colors_named_from_prop_cycle(self, num_colors, expected):
+        import matplotlib as mpl
+        from matplotlib.pyplot import cycler
+
+        mpl_params = {
+            "axes.prop_cycle": cycler(color=["red", "green", "blue"]),
+        }
+        with mpl.rc_context(rc=mpl_params):
+            result = get_standard_colors(num_colors=num_colors)
+            assert result == expected
+
+    @pytest.mark.parametrize(
+        "num_colors, expected",
+        [
+            (1, ["b"]),
+            (3, ["b", "g", "r"]),
+            (4, ["b", "g", "r", "y"]),
+            (5, ["b", "g", "r", "y", "b"]),
+            (7, ["b", "g", "r", "y", "b", "g", "r"]),
+        ],
+    )
+    def test_default_colors_named_from_prop_cycle_string(self, num_colors, expected):
+        import matplotlib as mpl
+        from matplotlib.pyplot import cycler
+
+        mpl_params = {
+            "axes.prop_cycle": cycler(color="bgry"),
+        }
+        with mpl.rc_context(rc=mpl_params):
+            result = get_standard_colors(num_colors=num_colors)
+            assert result == expected
+
+    @pytest.mark.parametrize(
+        "num_colors, expected_name",
+        [
+            (1, ["C0"]),
+            (3, ["C0", "C1", "C2"]),
+            (
+                12,
+                [
+                    "C0",
+                    "C1",
+                    "C2",
+                    "C3",
+                    "C4",
+                    "C5",
+                    "C6",
+                    "C7",
+                    "C8",
+                    "C9",
+                    "C0",
+                    "C1",
+                ],
+            ),
+        ],
+    )
+    def test_default_colors_named_undefined_prop_cycle(self, num_colors, expected_name):
+        import matplotlib as mpl
+        import matplotlib.colors as mcolors
+
+        with mpl.rc_context(rc={}):
+            expected = [mcolors.to_hex(x) for x in expected_name]
+            result = get_standard_colors(num_colors=num_colors)
+            assert result == expected
+
+    @pytest.mark.parametrize(
+        "num_colors, expected",
+        [
+            (1, ["red", "green", (0.1, 0.2, 0.3)]),
+            (2, ["red", "green", (0.1, 0.2, 0.3)]),
+            (3, ["red", "green", (0.1, 0.2, 0.3)]),
+            (4, ["red", "green", (0.1, 0.2, 0.3), "red"]),
+        ],
+    )
+    def test_user_input_color_sequence(self, num_colors, expected):
+        color = ["red", "green", (0.1, 0.2, 0.3)]
+        result = get_standard_colors(color=color, num_colors=num_colors)
+        assert result == expected
+
+    @pytest.mark.parametrize(
+        "num_colors, expected",
+        [
+            (1, ["r", "g", "b", "k"]),
+            (2, ["r", "g", "b", "k"]),
+            (3, ["r", "g", "b", "k"]),
+            (4, ["r", "g", "b", "k"]),
+            (5, ["r", "g", "b", "k", "r"]),
+            (6, ["r", "g", "b", "k", "r", "g"]),
+        ],
+    )
+    def test_user_input_color_string(self, num_colors, expected):
+        color = "rgbk"
+        result = get_standard_colors(color=color, num_colors=num_colors)
+        assert result == expected
+
+    @pytest.mark.parametrize(
+        "num_colors, expected",
+        [
+            (1, [(0.1, 0.2, 0.3)]),
+            (2, [(0.1, 0.2, 0.3), (0.1, 0.2, 0.3)]),
+            (3, [(0.1, 0.2, 0.3), (0.1, 0.2, 0.3), (0.1, 0.2, 0.3)]),
+        ],
+    )
+    def test_user_input_color_floats(self, num_colors, expected):
+        color = (0.1, 0.2, 0.3)
+        result = get_standard_colors(color=color, num_colors=num_colors)
+        assert result == expected
+
+    @pytest.mark.parametrize(
+        "color, num_colors, expected",
+        [
+            ("Crimson", 1, ["Crimson"]),
+            ("DodgerBlue", 2, ["DodgerBlue", "DodgerBlue"]),
+            ("firebrick", 3, ["firebrick", "firebrick", "firebrick"]),
+        ],
+    )
+    def test_user_input_named_color_string(self, color, num_colors, expected):
+        result = get_standard_colors(color=color, num_colors=num_colors)
+        assert result == expected
+
+    @pytest.mark.parametrize("color", ["", [], (), Series([], dtype="object")])
+    def test_empty_color_raises(self, color):
+        with pytest.raises(ValueError, match="Invalid color argument"):
+            get_standard_colors(color=color, num_colors=1)
+
+    @pytest.mark.parametrize(
+        "color",
+        [
+            "bad_color",
+            ("red", "green", "bad_color"),
+            (0.1,),
+            (0.1, 0.2),
+            (0.1, 0.2, 0.3, 0.4, 0.5),  # must be either 3 or 4 floats
+        ],
+    )
+    def test_bad_color_raises(self, color):
+        with pytest.raises(ValueError, match="Invalid color"):
+            get_standard_colors(color=color, num_colors=5)