Ellipsis

[scidam]

I am not sure I can understand you, may be this is because I am not a native English speaker. Are you talking about passing arguments to a function, or overriding dictionary methods, e.g. dict.__getitem__? Could you provide some code: where it was used None and where you want to use Ellipsis instead. If you need to override dict.__getitem__, you need to subclass UserDict instead of dict:

from collections import UserDict

class option(UserDict):
    def __getitem__(self, key):
        if key is Ellipsis:
            print("Do some stuff")
        else:
            return super().__getitem__(key)

z = option()
z.update({'one': 1})
z[...]

Hope that helps...