Kontrolna številka osebnega dokumenta

NUM = {"E": 14, "I": 18}
for i in range(10):
    NUM[str(i)] = i


def crc(sr):
    assert len(sr) == 9
    sum = 0
    for a, b in zip([NUM[x] for x in sr], (7, 3, 1)*3):
        sum += a * b
    return sum % 10


assert crc("IE9876543") == 0