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Flake8 Builtins plugin
======================
Check for python builtins being used as variables or parameters.
Imagine some code like this:
.. code:: Python
def max_values(list, list2):
max = list[0]
for x in list:
if x > 0:
max = x
all_values = list()
all_values.append(max)
max = list2[0]
for x in list2:
if x > 0:
max = x
all_values.append(max)
return all_values
max_values([3, 4, 5,], [5, 6, 7])
The last statement is not returning ``[5, 7]`` as one would expect,
instead is raising this exception::
Traceback (most recent call last):
File "test.py", line 17, in
max_values([3,4,5], [4,5,6])
File "bla.py", line 6, in max_values
all_values = list()
TypeError: 'list' object is not callable
**Why?** Because max_value function's first argument is list a Python
builtin.
Python allows to override them, but although could be useful in some really
specific use cases,
the general approach is to **not** do that as code then can suddenly break
without a clear trace.
Example
-------
Given the following code:
.. code:: Python
def my_method(object, list, dict):
max = 5
min = 3
zip = (4, 3)
The following warnings are shown (via flake8)::
test.py:1:15: A002 argument "object" is shadowing a python builtin
test.py:1:23: A002 argument "list" is shadowing a python builtin
test.py:1:29: A002 argument "dict" is shadowing a python builtin
test.py:2:5: A001 variable "max" is shadowing a python builtin
test.py:3:5: A001 variable "min" is shadowing a python builtin
test.py:4:5: A001 variable "zip" is shadowing a python builtin
Install
-------
Install with pip::
$ python -m pip install flake8-builtins
Options
-------
One can use `--builtins-ignorelist` option, or configuration option,
to ignore a custom list of builtins::
$ flake8 --builtins-ignorelist id,copyright *.py
Requirements
------------
- Python 3.8, 3.9, 3.10, 3.11, 3.12, and pypy3
- flake8
Rules
-----
A001:
A variable is shadowing a Python builtin.
A002:
An argument is shadowing a Python builtin.
A003:
A class attribute is shadowing a Python builtin.
A004:
An import statement is shadowing a Python builtin.
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