expr-1 if bool-expr else expr-2

def int_to_float(v):
return float(v) if isinstance(v, int) else 0.0

true_val if condition else false_val

so:

def int_to_float(v):
return 0.0 if type(v) != int else float(v)

If you need to be compatible with older versions though you are stuck of course. Also as you probably know but just as a note for anyone that happens across this, direct type comparisons as used in the examples above are discouraged since it will break any chance of duck types working.