Counting leading zeros

Question

I have a basic function:

    return len(a) - len(str(int(a)))

When this is run against the value of: 0000
It returns 3 rather than 4.

I really do not understand why, can someone please clarify?

Answer 1

Try this:

if int(a) == 0:
    nb_zeros = len(a)
else:
    nb_zeros = len(a) - len(str(int(a)))

print(nb_zeros)