Incorrect argument substitution on Unpack[tuple[...]] #118168
Description
Bug report
Bug description:
In the code below, all of the prints should be equivalent:
from typing import Generic, Tuple, TypeVarTuple, Unpack
Ts = TypeVarTuple("Ts")
class Old(Generic[*Ts]): ...
class New[*Ts]: ...
PartOld = Old[int, *Ts]
print(PartOld[str])
print(PartOld[*tuple[str]])
print(PartOld[*Tuple[str]])
print(PartOld[Unpack[tuple[str]]]) # Old[int, typing.Unpack[tuple[str]]]
print(PartOld[Unpack[Tuple[str]]])
PartNew = New[int, *Ts]
print(PartNew[str])
print(PartNew[*tuple[str]])
print(PartNew[*Tuple[str]])
print(PartNew[Unpack[tuple[str]]]) # New[int, typing.Unpack[tuple[str]]]
print(PartNew[Unpack[Tuple[str]]])However, the Unpack[tuple[]] variants print something different. This is because the implementation of Unpack doesn't deal correctly with builtin aliases. I'll send a PR.
CPython versions tested on:
3.12, CPython main branch
Operating systems tested on:
macOS