Incorrect type repr of empty tuples and namedtuples #15782
Description
Right now this code will produce:
from typing import NamedTuple
N = NamedTuple('N', [])
n: N
reveal_type(N) # N: Revealed type is "def () -> Tuple[, fallback=__main__.N]"
reveal_type(n) # N: Revealed type is "Tuple[, fallback=__main__.N]"and:
from typing import Tuple
def f() -> Tuple[()]: ...
reveal_type(f) # N: Revealed type is "def () -> Tuple[]"
reveal_type(f()) # N: Revealed type is "Tuple[]"This does not look right, because Tuple[] is not a thing in Python:
>>> from typing import Tuple
>>> Tuple[]
File "<stdin>", line 1
Tuple[]
^
SyntaxError: invalid syntaxI propose to change it to tuple[()] or Tuple[()] with optional fallback= in case of NamedTuple.
This can affect people who assert output (like pytest-mypy-plugins users), but I think that /s/Tuple[]/Tuple[()] is simple enough to fix all output based checks.
But, we will be more correct in terms of typing.