first commit

This commit is contained in:
Ayxan
2022-05-23 00:16:32 +04:00
commit d660f2a4ca
24786 changed files with 4428337 additions and 0 deletions

View File

@ -0,0 +1 @@
pip

View File

@ -0,0 +1,21 @@
MIT License
Copyright (c) 2019 Alex Hall
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

View File

@ -0,0 +1,229 @@
Metadata-Version: 2.1
Name: pure-eval
Version: 0.2.2
Summary: Safely evaluate AST nodes without side effects
Home-page: http://github.com/alexmojaki/pure_eval
Author: Alex Hall
Author-email: alex.mojaki@gmail.com
License: MIT
Platform: UNKNOWN
Classifier: Intended Audience :: Developers
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Classifier: Programming Language :: Python :: 3.10
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Description-Content-Type: text/markdown
License-File: LICENSE.txt
Provides-Extra: tests
Requires-Dist: pytest ; extra == 'tests'
# `pure_eval`
[![Build Status](https://travis-ci.org/alexmojaki/pure_eval.svg?branch=master)](https://travis-ci.org/alexmojaki/pure_eval) [![Coverage Status](https://coveralls.io/repos/github/alexmojaki/pure_eval/badge.svg?branch=master)](https://coveralls.io/github/alexmojaki/pure_eval?branch=master) [![Supports Python versions 3.5+](https://img.shields.io/pypi/pyversions/pure_eval.svg)](https://pypi.python.org/pypi/pure_eval)
This is a Python package that lets you safely evaluate certain AST nodes without triggering arbitrary code that may have unwanted side effects.
It can be installed from PyPI:
pip install pure_eval
To demonstrate usage, suppose we have an object defined as follows:
```python
class Rectangle:
def __init__(self, width, height):
self.width = width
self.height = height
@property
def area(self):
print("Calculating area...")
return self.width * self.height
rect = Rectangle(3, 5)
```
Given the `rect` object, we want to evaluate whatever expressions we can in this source code:
```python
source = "(rect.width, rect.height, rect.area)"
```
This library works with the AST, so let's parse the source code and peek inside:
```python
import ast
tree = ast.parse(source)
the_tuple = tree.body[0].value
for node in the_tuple.elts:
print(ast.dump(node))
```
Output:
```python
Attribute(value=Name(id='rect', ctx=Load()), attr='width', ctx=Load())
Attribute(value=Name(id='rect', ctx=Load()), attr='height', ctx=Load())
Attribute(value=Name(id='rect', ctx=Load()), attr='area', ctx=Load())
```
Now to actually use the library. First construct an Evaluator:
```python
from pure_eval import Evaluator
evaluator = Evaluator({"rect": rect})
```
The argument to `Evaluator` should be a mapping from variable names to their values. Or if you have access to the stack frame where `rect` is defined, you can instead use:
```python
evaluator = Evaluator.from_frame(frame)
```
Now to evaluate some nodes, using `evaluator[node]`:
```python
print("rect.width:", evaluator[the_tuple.elts[0]])
print("rect:", evaluator[the_tuple.elts[0].value])
```
Output:
```
rect.width: 3
rect: <__main__.Rectangle object at 0x105b0dd30>
```
OK, but you could have done the same thing with `eval`. The useful part is that it will refuse to evaluate the property `rect.area` because that would trigger unknown code. If we try, it'll raise a `CannotEval` exception.
```python
from pure_eval import CannotEval
try:
print("rect.area:", evaluator[the_tuple.elts[2]]) # fails
except CannotEval as e:
print(e) # prints CannotEval
```
To find all the expressions that can be evaluated in a tree:
```python
for node, value in evaluator.find_expressions(tree):
print(ast.dump(node), value)
```
Output:
```python
Attribute(value=Name(id='rect', ctx=Load()), attr='width', ctx=Load()) 3
Attribute(value=Name(id='rect', ctx=Load()), attr='height', ctx=Load()) 5
Name(id='rect', ctx=Load()) <__main__.Rectangle object at 0x105568d30>
Name(id='rect', ctx=Load()) <__main__.Rectangle object at 0x105568d30>
Name(id='rect', ctx=Load()) <__main__.Rectangle object at 0x105568d30>
```
Note that this includes `rect` three times, once for each appearance in the source code. Since all these nodes are equivalent, we can group them together:
```python
from pure_eval import group_expressions
for nodes, values in group_expressions(evaluator.find_expressions(tree)):
print(len(nodes), "nodes with value:", values)
```
Output:
```
1 nodes with value: 3
1 nodes with value: 5
3 nodes with value: <__main__.Rectangle object at 0x10d374d30>
```
If we want to list all the expressions in a tree, we may want to filter out certain expressions whose values are obvious. For example, suppose we have a function `foo`:
```python
def foo():
pass
```
If we refer to `foo` by its name as usual, then that's not interesting:
```python
from pure_eval import is_expression_interesting
node = ast.parse('foo').body[0].value
print(ast.dump(node))
print(is_expression_interesting(node, foo))
```
Output:
```python
Name(id='foo', ctx=Load())
False
```
But if we refer to it by a different name, then it's interesting:
```python
node = ast.parse('bar').body[0].value
print(ast.dump(node))
print(is_expression_interesting(node, foo))
```
Output:
```python
Name(id='bar', ctx=Load())
True
```
In general `is_expression_interesting` returns False for the following values:
- Literals (e.g. `123`, `'abc'`, `[1, 2, 3]`, `{'a': (), 'b': ([1, 2], [3])}`)
- Variables or attributes whose name is equal to the value's `__name__`, such as `foo` above or `self.foo` if it was a method.
- Builtins (e.g. `len`) referred to by their usual name.
To make things easier, you can combine finding expressions, grouping them, and filtering out the obvious ones with:
```python
evaluator.interesting_expressions_grouped(root)
```
To get the source code of an AST node, I recommend [asttokens](https://github.com/gristlabs/asttokens).
Here's a complete example that brings it all together:
```python
from asttokens import ASTTokens
from pure_eval import Evaluator
source = """
x = 1
d = {x: 2}
y = d[x]
"""
names = {}
exec(source, names)
atok = ASTTokens(source, parse=True)
for nodes, value in Evaluator(names).interesting_expressions_grouped(atok.tree):
print(atok.get_text(nodes[0]), "=", value)
```
Output:
```python
x = 1
d = {1: 2}
y = 2
d[x] = 2
```

View File

@ -0,0 +1,17 @@
pure_eval-0.2.2.dist-info/INSTALLER,sha256=zuuue4knoyJ-UwPPXg8fezS7VCrXJQrAP7zeNuwvFQg,4
pure_eval-0.2.2.dist-info/LICENSE.txt,sha256=pHaiyw70xBRQNApXeii5GsTH9mkTay7hSAR_q9X8QYE,1066
pure_eval-0.2.2.dist-info/METADATA,sha256=7ymWO8RGYzKetW67FHk45j-x3cig4U3pWAk2V-w5U38,6245
pure_eval-0.2.2.dist-info/RECORD,,
pure_eval-0.2.2.dist-info/WHEEL,sha256=G16H4A3IeoQmnOrYV4ueZGKSjhipXx8zc8nu9FGlvMA,92
pure_eval-0.2.2.dist-info/top_level.txt,sha256=aj24vzw3wc3XsL3Q0sHidIX6N7TaViEDr1R_R4Qbgjo,10
pure_eval/__init__.py,sha256=epP1aW7z2hYB0FtC_x3w1AFlnhSgn4UVkRamFlVfXd4,285
pure_eval/__pycache__/__init__.cpython-310.pyc,,
pure_eval/__pycache__/core.cpython-310.pyc,,
pure_eval/__pycache__/my_getattr_static.cpython-310.pyc,,
pure_eval/__pycache__/utils.cpython-310.pyc,,
pure_eval/__pycache__/version.cpython-310.pyc,,
pure_eval/core.py,sha256=bxshWghVwCawdVfrNdXLqHj5UOpaPz1aAkB0T3xh_3Q,15309
pure_eval/my_getattr_static.py,sha256=JvAM30EQcf7RQKG3fYSJT1tiwEKbkPnpqPRWXjIoV8o,4076
pure_eval/py.typed,sha256=w3xYJo71zA7pDnF65xr6u8FL8gvJ7GdAKMJSLuv2IPU,68
pure_eval/utils.py,sha256=eSI-lVyBzYW1D2vRQPrvhXPhQpRArhv_GoBx1AIfWHc,4415
pure_eval/version.py,sha256=pKh2_hmFNUwG0JxbL18qxdmi_nmFpgRbR8X6IPZr08o,21

View File

@ -0,0 +1,5 @@
Wheel-Version: 1.0
Generator: bdist_wheel (0.37.1)
Root-Is-Purelib: true
Tag: py3-none-any

View File

@ -0,0 +1 @@
pure_eval