DictWriter signed as unsubscriptable

[clo-vis]

Bug description

from csv import DictWriter
from typing import IO


def f_is_for_fun(file: IO[str]) -> DictWriter[str]:
    return DictWriter(file, ["id", "name"])

Command used

pylint playground.py

Pylint output

************* Module playground
...
playground.py:5:35: E1136: Value 'DictWriter' is unsubscriptable (unsubscriptable-object)

Expected behavior

No error, as DictWriter is defined as class DictWriter(Generic[_T]) (https://github.com/python/typeshed/blob/master/stdlib/csv.pyi)

On a side note, mypy doesn't complain about the code, but it does complain for

def f_is_for_fun(file: IO[str]) -> DictWriter:
    return DictWriter(file, ["id", "name"])

Missing type parameters for generic type "DictWriter" [type-arg]

Pylint version

pylint 2.13.8
astroid 2.11.4
Python 3.9.12 (tags/v3.9.12:b28265d, Mar 23 2022, 23:52:46) [MSC v.1929 64 bit (AMD64)]

OS / Environment

Microsoft Windows [Version 10.0.19042.1645]

[cdce8p]

The error is correct. At runtime, DictWriter is unsubscriptable and will raise a TypeError.
You need to use string annotations or PEP585 from __future__ import annotations. That will also hide the pylint error.

https://mypy.readthedocs.io/en/stable/runtime_troubles.html#using-classes-that-are-generic-in-stubs-but-not-at-runtime