Allow `float("inf")` and `float("-inf")` in literals

I have been frequently using positive and negative infinity as default values for values that should otherwise be ints. Because of Python's duck typing this is a convenient pattern that sometimes allows reducing some special-casing logic.

def less_than(value: int, limit: int | None) -> bool:
    if limit is None:
        return True
    return value < limit

vs

def less_than(value: int, limit: int | Literal[float("inf")]) -> bool:
    return value < limit

Would it be feasible to special-case the expressions float("inf") and float("-inf") and make type-checkers regard them as literal values, even though they aren't strictly speaking language-level literals?

For posterity, PEP 586 mentions this with:

Representing Literals of infinity or NaN in a clean way is tricky; real-world APIs are unlikely to vary their behavior based on a float parameter.

So I guess what I'm asking here is: am I an odd duckling or could it be worth considering +/- infinity as legal values in literal types?

Commencez par lire la discussion de la PEP 586 sur les paramètres Literal illégaux ainsi que les 21 commentaires de cette issue. Déterminez si la communauté du typage est parvenue à une décision concernant le traitement de float("inf") et de float("-inf") comme valeurs littérales ; la tâche ne serait terminée que si une spécification faisant consensus et les modifications à apporter aux type-checkers avaient été identifiées, ce que l’issue ne fournit pas.