Add "dynamic-modules" option to allow for checking member attributes dynamically (patch attached)

[pylint-bot]

Originally reported by: Czarek Tomczak (BitBucket: Czarek, GitHub: @Czarek?)

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I have this code that uses the wxPython library:

#!python

import wx
frame = wx.Frame(None, -1, "Hello World")

Pylint will throw an error:

#!text
E: 15,15: Module 'wx' has no 'Frame' member (no-member)

A similar issue for the numpy library was reported in the past, see Issue 58:

58/

That case was fixed for numpy, but there are still similar issues with many other libraries. There is a "ignore-modules" option, but using it is not a good idea, as it will ignore real problems when accessing non existent members. In a comment by Mykola Sakhno it was proposed to add a "dynamic-modules" option as a solution for this problem.

Attaching the "pylint_1.4.0_dynamic_modules.patch" file. It adds "dynamic-modules" option and a new method visit_getattr_dynamic() in pylint/checkers/typecheck.py > TypeChecker class. I know that this code isn't perfect, but it's a good start, it works.

The .pylintrc rcfile looks like this:

#!text
[TYPECHECK]
ignored-modules=
dynamic-modules=wx,asd.xyz

The example script I'm using tests two cases: a shared package and a local package. See:

#!python
import wx # a package installed to /lib/site-packages/
import asd.xyz # a local package in application's directory
frame = wx.Frame(None, -1, "Hello World")
asd.xyz.Frame(None, -1, "Hello World")

Without the patch this errors appear in pylint:

#!text
E: 15,15: Module 'wx' has no 'Frame' member (no-member)
E: 16,12: Module 'asd.xyz' has no 'Frame' member (no-member)

After applying patch, these errors disappear. All looks to be working fine.

Using pylint 1.4.0 and Python 3.4.2 on Windows 7. The patch should work with Python 2.7 as well.

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• Bitbucket: https://bitbucket.org/logilab/pylint/issue/413

[pylint-bot]

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

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Thanks for the patch! Could you submit it as a pull request? It's much easier to review that way.

[pylint-bot]

Original comment by Czarek Tomczak (BitBucket: Czarek, GitHub: @Czarek?):

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@PCManticore Created pull request #208.

[pylint-bot]

Original comment by Czarek Tomczak (BitBucket: Czarek, GitHub: @Czarek?):

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Found another related Issue #357. Looks like in the past there were probably many manual fixes required like the one in this commit. The "dynamic-modules" option might be a solution to such issues in the future.

[pylint-bot]

Original comment by Czarek Tomczak (BitBucket: Czarek, GitHub: @Czarek?):

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There is another kind of error message that isn't handled by this patch and which is also caused by dynamic names:

#!python
from wx.core import *

Results in error:

#!text
E: 12, 0: No name 'core' in module 'wx' (no-name-in-module)

But it's strange as later it complains about specific things being imported from wx.core, so it must have found that "core" name somewhat:

#!text
W: 12, 0: Wildcard import wx.core (wildcard-import)
W: 12, 0: Unused import wxEVT_COMMAND_LISTBOOK_PAGE_CHANGING from wildcard import (unused-wildcard-import)
W: 12, 0: Unused import wxEVT_COMMAND_CHOICE_SELECTED from wildcard import (unused-wildcard-import)
W: 12, 0: Unused import EVT_COMBOBOX from wildcard import (unused-wildcard-import)
...