False positive E1136: Value 'typing.ChainMap' is unsubscriptable (unsubscriptable-object)

[jhbuhrman]

Steps to reproduce

1. Create the following file named pylint_chainmap.py:

import typing
from collections import ChainMap


def check_pylint_chain_map() -> typing.ChainMap[str, typing.Any]:
    return ChainMap({"answer": 42})

2. pylint --reports=n --score=n --disable=C0111 pylint_chainmap.py

Please note that mypy is perfectly happy with this source file.

Current behavior

************* Module pylint_chainmap
pylint_chainmap.py:5:32: E1136: Value 'typing.ChainMap' is unsubscriptable (unsubscriptable-object)

Expected behavior

pylint --version output

pylint 2.3.1
astroid 2.2.5
Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)]

[jhbuhrman]

Might it have something to do with the conditional definition in typing.py:2036? ...

if hasattr(collections, 'ChainMap'):
    # ChainMap only exists in 3.3+
    __all__.append('ChainMap')

    class ChainMap(collections.ChainMap, MutableMapping[KT, VT],
                   extra=collections.ChainMap):

    ...

[PCManticore]

@jhbuhrman It's entirely possible that the inference is tripped by the conditional definition. We need to add support for some typing constructs in astroid, the library that pylint uses for type inference.

[cdce8p]

This issue seems to be fixed when testing with the latest pylint version.
If you still encounter issues, please report back and I'll reopen it.