import cython @cython.locals(counts=cython.int[10], digit=cython.int) def count_digits(digits): """ >>> digits = '01112222333334445667788899' >>> count_digits(map(int, digits)) [1, 3, 4, 5, 3, 1, 2, 2, 3, 2] """ counts = [0] * 10 for digit in digits: assert 0 <= digit <= 9 counts[digit] += 1 return counts