Sounds like you want 'newtypes', e.g. XCoord = NewType("XCoord", int) YCoord = NewType("YCoord", int) Point = NewType("Point", Tuple[XCoord, YCoord

Sounds like you want 'newtypes', e.g. XCoord = NewType("XCoord", int) YCoord = NewType("YCoord", int) Point = NewType("Point", Tuple[XCoord, YCoord]) These are just new names for existing types (in this case the existing types `int` and `Tuple[int, int]`); they make no difference to the way the code actually runs (unlike, say, introducing a new class). However, checkers like Mypy will not let us mix up these newtypes with their underlying types. For example, if a function requires a `Point`, Mypy will complain if we try to call it with a `Tuple[int, int]`. Newtypes are useful for keeping semantically-distinct types separate, even if they just-so-happen to use the same underlying implementation. In other words, they let us selectively avoid duck-typing if it might cause problems. Of course, this is only useful if the code we're calling actually exposes such types!