C does different things for 0.0 / 0.0 and 0 / 0 and it's not that weird to deal with (well it has other issues like it being platform dependent what happens with this). JS has no problem with it either (0.0 / 0.0 gives nan, 0n / 0n gives exception since it are integers).

Python is the only language doing this (of the ones I use at least).

I don't think the notation `x: float = 0` existed when it was new by the way so that can't be the design reason?

since python seems to handle integer through integer divisions as float (e.g. 5 / 2 outputs 2.5), 0 / 0 giving nan would seem to be expected there

> liskov substitution principle

that would imply one is a subtype of another, is that really the case here? there are floats that can't be represented as an integer (e.g. 0.5) and integers that can't be represented as a double precision float (e.g. 18446744073709551615)