def exact_sqrt(n2):
    "If n2 is a perfect square, return its square root, else raise error."
    n = int(math.sqrt(n2))
    assert n * n == n2
    return n
def exact_sqrt(n2):
    "If n2 is a perfect square, return its square root, else raise error."
    n = int(math.sqrt(n2))
    assert n * n == n2
    return n
def exact_sqrt ( n2 ) : n = int ( math . sqrt ( n2 ) ) assert n * n == n2 return n
If n2 is a perfect square, return its square root, else raise error.
If n2 is a perfect square return its square root else raise error .