Wemake-python-styleguide: WPS425 boolean non-keyword argument clashes with setdefault

Created on 16 Jan 2020 · 7Comments · Source: wemake-services/wemake-python-styleguide

Bug report

What's wrong

example_dict = {}
example_dict.setdefault("value", True)
>>> WPS425 Found boolean non-keyword argument

example_dict = {}
example_dict.setdefault("value", default=True)
>>> TypeError: setdefault() takes no keyword arguments

How is that should be

Not sure. Maybe there should be a whitelist of allowed methods/functions?

System information

Python 3.7.4

flake8 information

Contents of flake8 --bug-report:

flake info

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Related #1085

bug

Source

AlwxSin

All 7 comments

My recommendation is just to ignore (noqa) this case.

sobolevn on 16 Jan 2020

I can't agree with that. Ignoring is an option if I have choices. Python linter should not violate python api itself if this api is allowed.

AlwxSin on 16 Jan 2020

The problem is that Python API is inconsistent as f. They actually had to create / params to fix it.

Why I don't like to create any kind of whitelist here: it is really hard to cover all cases correctly.
For example: one can have def setdefault(self, key, default): in their own class. And it would be a violation not to provide a keyword here. So, we cannot be sure when we are based on names, not types.

I am going to work on this soon enough, I have a working prototype of type inferring mechanism that works for our case.

Another option is to just turn off this check.

sobolevn on 16 Jan 2020

😕1

This will be fixed in typed-linter one day.

sobolevn on 18 Jan 2020

This isn't worth opening a new Issue, but I found similar behavior when appending booleans to a list, like: a_list.append(True). Using the keyword argument object causes an error. If anyone finds this comment and doesn't want to use noqa, you can use a_list.extend([True]) as a workaround.