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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def hamming_distance(s1, s2, equality_function=operator.eq):
 """ Returns the hamming distance between two strings. """

    if not len(s1) == len(s2):
        raise ValueError("String lengths are not equal")

    # Number of non-matching characters:
    return sum(not equality_function(c1, c2) for c1, c2 in zip(s1, s2))