Python implementation of the Fermat Primality Test

fermat.py

def fermat_test(n, k):

    # Implementation uses the Fermat Primality Test
    
    # If number is even, it's a composite number

    if n == 2:
        return True

    if n % 2 == 0:
        return False

    for i in xrange(k):
        a = random.randint(1, n-1)

        if pow(a, n-1) % n != 1:
            return False
    return True

Difficult right? @andWhatShouldISay