Python：求任意数字最高位是第几位【针对所有数字类型的通用方案】

import math

def maximum_number_of_digits(num: float):
    """
    :param num:
    :return: 个位是第0位，小数点后第一位是-1位，以此类推~
    """
    if num == 0:
        return None
    return math.floor(math.log10(abs(num)))


assert maximum_number_of_digits(5201314) == 6
assert maximum_number_of_digits(-5201314) == 6
assert maximum_number_of_digits(520.1314) == 2
assert maximum_number_of_digits(1/5) == -1
assert maximum_number_of_digits(math.pi) == 0
assert maximum_number_of_digits(0.000000000000000001) == -18
assert maximum_number_of_digits(0) is None