https://app.codility.com/demo/results/trainingEZPSHD-KKN/

binary_gap.py

def solution(N):
    max_length = 0
    length = 0
    quotient = N
    remainder = 0
    is_occur_one = False
    while quotient > 0:
        quotient, remainder = divmod(quotient, 2)
        if is_occur_one:
            if remainder == 1:
                max_length = length if length > max_length else max_length
                length = 0
            else:
                length += 1
        elif remainder == 1:
            is_occur_one = True
    
    return max_length