Should dict() constructor overloads be more permissive?

Current constructor overloads are here:

https://github.com/python/typeshed/blob/e80ad6b2bce7ef6b2a20aec2d79a672859b31864/stdlib/builtins.pyi#L1041-L1046

Someone took care to allow specific positive case, and to block specific negative case.
Many potential valid uses have fallen through the cracks:

dict([[1, 2]])
dict("AT TA GC CG".split())
dict([["str", b"bytes"]])

My understanding of the issue is that there's no way to specify sequence length (other than a tuple) in a type hint, that is there's no syntax to hint ["a", "b"] vs ["a", "b", "c"].

This brings a philosophical question: what side should typeshed err on when type hint syntax is not precise enough?

• type whatever Python may accept run time, or
• restrict users to what Python is guaranteed to accept at run time?

It was mentioned at https://github.com/microsoft/pyright/issues/7382 that type checkers trust typeshed, and thus the question belongs here.

My personal preference would be for permissive type hints in these cases.

Beginne mit stdlib/builtins.pyi bei den verlinkten Overloads des dict()-Konstruktors und vergleiche sie mit den Beispielaufrufen im Issue. Prüfe, wie die relevanten Type Checker diese Fälle behandeln, und ermittle anschließend, ob die beabsichtigte Richtlinie darin besteht, breitere zur Laufzeit gültige Eingaben zu akzeptieren; für den Abschluss sind ein abgestimmtes Overload-Design und die entsprechende Validierung erforderlich.