I need to use an iterable and a loop variable as a class property. But the flake8 checker produces B2020 warning:
easy.py:11:13: B020 Found for loop that reassigns the iterable it is iterating with each iterable value.
If I use a variable for iterable there is OK.
What is wrong?
The warning example:
#!/usr/bin/env python3
"""Example of B020 error."""
class My_Template:
"""My example."""
def __init__(self, *template):
"""Obviously init."""
self.all_templates = (1, 2, 3)
for self.tpl in self.all_templates:
print(self.tpl)
The flake8 complains about loop variable:
easy.py:11:13: B020 Found for loop that reassigns the iterable it is iterating with each iterable value.
The OK example:
#!/usr/bin/env python3
"""Example of B020 error."""
class My_Template:
"""My example."""
def __init__(self, *template):
"""Obviously init."""
all_templates = (1, 2, 3)
for self.tpl in all_templates:
print(self.tpl)
Answer
It's a known issue:
https://github.com/PyCQA/flake8-bugbear/issues/248
Understandably flake8-bugbear developers are a bit unwilling to fix this as it's not very common to use an instance attribute as the loop variable. It's also not really needed. You can simply use a normal loop variable:
class My_Template:
def __init__(self, *template):
self.all_templates = (1, 2, 3)
for tpl in self.all_templates:
self.tpl = tpl
print(self.tpl)
