Technically, we probably could, but would often need workarounds for code which changes the initial condition such as, i = 0 if i <= 0: i += 1 else

Technically, we probably could, but would often need workarounds for code which changes the initial condition such as, i = 0 if i <= 0: i += 1 else: i -= 1 You could of course solve this in various ways, for example something like: condition = i <= 0 if condition: i += 1 if not condition: i -= 1 But i don't find that to read as well as an else block. Also restating longer conditions which we don't change in the then-block to mimic an else with an if seems like a waste of spacetime.