Overlapping count of substring in a string in Python

Question

I want to find all the counts (overlapping and non-overlapping) of a sub-string in a string. I found two answers one of which is using regex which is not my intention and t

Answer 1

def sliding(a, n):
    return (a[i:i+n] for i in xrange(len(a) - n + 1))

def substring_count(a, b):
    return sum(s == b for s in sliding(a, len(b)))

assert list(sliding('abcde', 3)) == ['abc', 'bcd', 'cde']    
assert substring_count('ababaa', 'aba') == 2

Answer 2

Does this do the trick?

def count(string, substring):
    n = len(substring)
    cnt = 0
    for i in range(len(string) - n):
        if string[i:i+n] == substring:
            cnt += 1
    return cnt

print count('ababaa', 'aba') # 2

I don't know if there's a more efficient solution, but this should work.