# Copyright 2018-2022 Streamlit Inc. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. from textwrap import dedent from typing import Any, Callable, Optional, cast import streamlit from streamlit.errors import StreamlitAPIException from streamlit.proto.Slider_pb2 import Slider as SliderProto from streamlit.scriptrunner import ScriptRunContext, get_script_run_ctx from streamlit.state import ( register_widget, WidgetArgs, WidgetCallback, WidgetKwargs, ) from streamlit.type_util import Key, OptionSequence, ensure_indexable, to_key from streamlit.util import index_ from .form import current_form_id from .utils import check_callback_rules, check_session_state_rules class SelectSliderMixin: def select_slider( self, label: str, options: OptionSequence = [], value: Any = None, format_func: Callable[[Any], Any] = str, key: Optional[Key] = None, help: Optional[str] = None, on_change: Optional[WidgetCallback] = None, args: Optional[WidgetArgs] = None, kwargs: Optional[WidgetKwargs] = None, *, # keyword-only arguments: disabled: bool = False, ) -> Any: """ Display a slider widget to select items from a list. This also allows you to render a range slider by passing a two-element tuple or list as the `value`. The difference between `st.select_slider` and `st.slider` is that `select_slider` accepts any datatype and takes an iterable set of options, while `slider` only accepts numerical or date/time data and takes a range as input. Parameters ---------- label : str A short label explaining to the user what this slider is for. options : Sequence, numpy.ndarray, pandas.Series, pandas.DataFrame, or pandas.Index Labels for the slider options. All options will be cast to str internally by default. For pandas.DataFrame, the first column is selected. value : a supported type or a tuple/list of supported types or None The value of the slider when it first renders. If a tuple/list of two values is passed here, then a range slider with those lower and upper bounds is rendered. For example, if set to `(1, 10)` the slider will have a selectable range between 1 and 10. Defaults to first option. format_func : function Function to modify the display of the labels from the options. argument. It receives the option as an argument and its output will be cast to str. key : str or int An optional string or integer to use as the unique key for the widget. If this is omitted, a key will be generated for the widget based on its content. Multiple widgets of the same type may not share the same key. help : str An optional tooltip that gets displayed next to the select slider. on_change : callable An optional callback invoked when this select_slider's value changes. args : tuple An optional tuple of args to pass to the callback. kwargs : dict An optional dict of kwargs to pass to the callback. disabled : bool An optional boolean, which disables the select slider if set to True. The default is False. This argument can only be supplied by keyword. Returns ------- any value or tuple of any value The current value of the slider widget. The return type will match the data type of the value parameter. Examples -------- >>> color = st.select_slider( ... 'Select a color of the rainbow', ... options=['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'violet']) >>> st.write('My favorite color is', color) And here's an example of a range select slider: >>> start_color, end_color = st.select_slider( ... 'Select a range of color wavelength', ... options=['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'violet'], ... value=('red', 'blue')) >>> st.write('You selected wavelengths between', start_color, 'and', end_color) .. output:: https://share.streamlit.io/streamlit/docs/main/python/api-examples-source/widget.select_slider.py height: 450px """ ctx = get_script_run_ctx() return self._select_slider( label=label, options=options, value=value, format_func=format_func, key=key, help=help, on_change=on_change, args=args, kwargs=kwargs, disabled=disabled, ctx=ctx, ) def _select_slider( self, label: str, options: OptionSequence = [], value: Any = None, format_func: Callable[[Any], Any] = str, key: Optional[Key] = None, help: Optional[str] = None, on_change: Optional[WidgetCallback] = None, args: Optional[WidgetArgs] = None, kwargs: Optional[WidgetKwargs] = None, disabled: bool = False, ctx: Optional[ScriptRunContext] = None, ) -> Any: key = to_key(key) check_callback_rules(self.dg, on_change) check_session_state_rules(default_value=value, key=key) opt = ensure_indexable(options) if len(opt) == 0: raise StreamlitAPIException("The `options` argument needs to be non-empty") is_range_value = isinstance(value, (list, tuple)) def as_index_list(v): is_range_value = isinstance(v, (list, tuple)) if is_range_value: slider_value = [index_(opt, val) for val in v] start, end = slider_value if start > end: slider_value = [end, start] return slider_value else: # Simplify future logic by always making value a list try: return [index_(opt, v)] except ValueError: if value is not None: raise return [0] # Convert element to index of the elements slider_value = as_index_list(value) slider_proto = SliderProto() slider_proto.label = label slider_proto.format = "%s" slider_proto.default[:] = slider_value slider_proto.min = 0 slider_proto.max = len(opt) - 1 slider_proto.step = 1 # default for index changes slider_proto.data_type = SliderProto.INT slider_proto.options[:] = [str(format_func(option)) for option in opt] slider_proto.form_id = current_form_id(self.dg) if help is not None: slider_proto.help = dedent(help) def deserialize_select_slider(ui_value, widget_id=""): if not ui_value: # Widget has not been used; fallback to the original value, ui_value = slider_value # The widget always returns floats, so convert to ints before indexing return_value = list(map(lambda x: opt[int(x)], ui_value)) # type: ignore[no-any-return] # If the original value was a list/tuple, so will be the output (and vice versa) return tuple(return_value) if is_range_value else return_value[0] def serialize_select_slider(v): return as_index_list(v) current_value, set_frontend_value = register_widget( "slider", slider_proto, user_key=key, on_change_handler=on_change, args=args, kwargs=kwargs, deserializer=deserialize_select_slider, serializer=serialize_select_slider, ctx=ctx, ) # This needs to be done after register_widget because we don't want # the following proto fields to affect a widget's ID. slider_proto.disabled = disabled if set_frontend_value: slider_proto.value[:] = serialize_select_slider(current_value) slider_proto.set_value = True self.dg._enqueue("slider", slider_proto) return current_value @property def dg(self) -> "streamlit.delta_generator.DeltaGenerator": """Get our DeltaGenerator.""" return cast("streamlit.delta_generator.DeltaGenerator", self)