PyLint doesn't handle python six very well.

[pylint-bot]

Originally reported by: Thomas Grainger (BitBucket: graingert, GitHub: @graingert?)

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When using from six.moves import range pylint complains that built-ins are being overridden.

In actual fact it should complain that the built-in range is used rather than the forward-looking six.moves version.

https://bitbucket.org/logilab/pylint.org/issue/4

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• Bitbucket: https://bitbucket.org/logilab/pylint/issue/200

[pylint-bot]

Original comment by the mulhern (BitBucket: the_mulhern):

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I'm adding another pylint/six bad interaction.

Given the following:

#!python

import abc
from six import with_metaclass

class Junk(with_metaclass(abc.ABCMeta, object)):

    def __init__(self):
        super(Junk, self).__init__()

pylint reports

"E: 6, 4: Use of super on an old style class (super-on-old-class)"

Essentially, analyses can not detect that Junk extends object, and interprets the definition as an old style class.

This can be fixed by using add_metaclass instead of with_metaclass. Evidently, with_metaclass concocts a secret subclass from which Junk inherits directly so that it inherits from object only indirectly while add_metaclass does not.

There is a chance that this is a six bug, and not a pylint bug at all.

In any case, it does seem to have a workaround in most cases.

[pylint-bot]

Original comment by Claudiu Popa (BitBucket: PCManticore, GitHub: @PCManticore):

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Which version? With Pylint 1.2 and astroid from the tip I get no super-on-old-class, both Python 2 and 3.

[pylint-bot]

Original comment by Maxim Syabro (BitBucket: syabro, GitHub: @syabro?):

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With same behavior I can't use Serializer.data but it's defined in BaseSerializer

class Serializer(six.with_metaclass(SerializerMetaclass, BaseSerializer)):
    pass

[pylint-bot]

Original comment by Brett Cannon (BitBucket: brettcannon, GitHub: @brettcannon?):

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Are there any plans to address the issue with overriding built-ins that have changed in Python 3?

[pylint-bot]

Original comment by Claudiu Popa (BitBucket: PCManticore, GitHub: @PCManticore):

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No, the only plan I have, for now, is fixing the with_metaclass false positive. As always, pull requests are appreciated. :-)

[pylint-bot]

Original comment by Brett Cannon (BitBucket: brettcannon, GitHub: @brettcannon?):

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=) I figured as much. I figure the check could be modified to not check for a key list of changed built-ins while simultaneously checking if they are not overridden in python3.

[pylint-bot]

Original comment by Brett Cannon (BitBucket: brettcannon, GitHub: @brettcannon?):

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So how would you like to see the warning triggered when a built-in is replaced? This is an issue in Python 2/3 code as filter, map, zip, round, range, input, and open are all different in Python 3, so it's legitimate to replace them with the Python 3 version to get consistency.

Do you want to whitelist certain built-ins to not be warned for? Or is there some way to have a checker be tweaked based on another checker being on (i.e. the built-in replacement checker not checking whitelisted built-ins when another checker that warns against dangerous use of the built-ins is active)? Or are people simply expected to silence this warning manually?

[pylint-bot]

Original comment by Benoit C (BitBucket: dzen, GitHub: @dzen?):

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I think pylint should be aware of some specificities in six: importing from moves raises:

"from six.moves.urllib.error import URLError" raises no-name-in-module

[pylint-bot]

Original comment by Claudiu Popa (BitBucket: PCManticore, GitHub: @PCManticore):

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Try with the latest version from the repository, we have special support for six.moves. It will be released soon, as pylint 1.5.