unpack syntax¶

basedpython polyfills the PEP 646 starred-type syntax in variadic parameter annotations for Python versions below 3.11

transformation¶

# basedpython
def f(*args: *tuple[int, ...]):
    pass

# generated Python
from typing import Unpack
def f(*args: Unpack[tuple[int, ...]]):
    pass

the starred form (*T) is native in Python 3.11+. for earlier targets the equivalent Unpack[T] form is used instead

when it applies¶

the transform applies only to *args parameter annotations. starred expressions in other positions (unpacking in assignments, function calls, etc.) are never affected

--min-version interaction¶

when targeting Python 3.11 or later, the starred form is valid natively and the transform is a no-op