How do I count the trailing zeros in integer?

Question

I am trying to write a function that returns the number of trailing 0s in a string or integer. Here is what I am trying and it is not returning the correct values.

Answer 1

The question asks to count the trailing zeros in a string or integer. For a string, len(s) - len(s.rstrip('0')) is fine. But for an integer, presumably you don't want to convert it to a string first. In that case, use recursion:

def trailing_zeros(longint):
    assert(longint)
    return ~longint % 2 and trailing_zeros(longint/2) + 1