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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 _safe_str_cmp(a, b):
 """ Internal function to efficiently iterate over the hashes Regular string compare will bail at the earliest opportunity which allows timing attacks """

    if len(a) != len(b):
        return False
    rv = 0
    for x, y in zip(a, b):
        rv |= ord(x) ^ ord(y)
    return rv == 0