False-positive 405 & 414 on loop unpacking

[pawamoy]

Bug report

What's wrong

for kind, (model_class, list_model_class) in mapping.items():
    ...  # do things

...triggers WPS405 and WPS414.

405 says:

Use regular ast.Name variables. Or tuple of ast.Name variables. Star names are also fine.

I'm using a name and a tuple with two names. This should be OK right?

414 says to avoid side-effects. There are no side-effects when unpacking into kind, (model_class, list_model_class).

How it should work

No 405 or 414 triggered.

System information

flake8 information

Contents of flake8 --bug-report:

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pip information

Contents of pip freeze: sorry lots of private stuff, can sanitize and post if needed.

[Ajax-Light]

Hey, is this issue still open? I'd like to try my hand at it. I am at a loss for choosing a starting point though, any pointers would be appreciated 😊

[sobolevn]

Yes, @Ajax-Light! Thanks a lot!

[sobolevn]

We need to fix this line:

wemake-python-styleguide/wemake_python_styleguide/visitors/ast/loops.py

Line 277 in a7b36e8

self.add_violation(LoopVariableDefinitionViolation(node))

And this:

wemake-python-styleguide/wemake_python_styleguide/visitors/ast/builtins.py

Line 436 in c33fcaa

best_practices.WrongUnpackingViolation(node),

[Ajax-Light]

Hey @sobolevn ! Ran into some issues setting up the Dev-environment.

1. Can I safely ignore the warnings by flake8 here:
   
   I looked through the files and they don't seem to be harmful.
2. I'm new to virtualenv, so should i always run wps inside a virtualenv generated by poetry shell?

I'm new to this production-grade stuff, sorry for being a bother 😅

[Ajax-Light]

Never mind! I found the solution in the tutorial, I forget I'm in WSL all the time. I have a question though, does poetry install install all the dependencies required for wps? Because I had file-not-found errors for each of the autopep8 import-linter and other steps of the Makefile which i had resolved by pip3 install ing all the dependencies. Maybe whatever I install in a virtual environment gets reset the next time I run poetry shell ?

[sobolevn]

does poetry install install all the dependencies required for wps?

Yes, it does. We have a CI to ensure it 🙂

Maybe whatever I install in a virtual environment gets reset the next time I run poetry shell ?

It sould not. But, I can clearly see that your env has some problem. Glad, that you have solved them!

[Ajax-Light]

Hey @sobolevn, quick update, I'm still learning about the ast module and going thought the developer documentation in my free time. I need a couple of days to post a fix, feel free to unassign me if its too long. Cheers! 👍

[sobolevn]

@Ajax-Light no worries! We are not in a hurry.