implement __class_getitem__ for some classes in itertools module #112896
Description
Feature or enhancement
Proposal:
Currently only itertools.chain can be subscripted at runtime. I think most of other iterators should be subscriptable too.
Most of these classes are generic in typeshed, so typecheckers thing that subscripting them is fine, which is inconsistent with behaviour at runtime.
With pyright:
import itertools
x = itertools.cycle[str]('abc')
reveal_type(x) # cycle[str]At runtime:
>>> import itertools as it
>>> it.cycle[int]
File "<stdin>", line 1, in <module>
TypeError: type 'itertools.cycle' is not subscriptable
>>> it.count[int]
TypeError: type 'itertools.repeat' is not subscriptable
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: type 'itertools.accumulate' is not subscriptable
>>> it.chain[int] # this is the only subscriptable class in itertools module
itertools.chain[int]Has this already been discussed elsewhere?
No response given