5kyu_What_is_a_perfect_power_anyway.py

"""
A perfect power is a classification of positive integers:

    In mathematics, a perfect power is a positive integer that can be expressed as an integer power of another positive integer. More formally, n is a perfect power if there exist natural numbers m > 1, and k > 1 such that mk = n.

Your task is to check wheter a given integer is a perfect power. If it is a perfect power, return a pair m and k with mk = n as a proof. Otherwise return Nothing, Nil, null, NULL, None or your language's equivalent.

Note: For a perfect power, there might be several pairs. For example 81 = 3^4 = 9^2, so (3,4) and (9,2) are valid solutions. However, the tests take care of this, so if a number is a perfect power, return any pair that proves it.
Examples

isPP(4) => [2,2]
isPP(9) => [3,2]
isPP(5) => None

"""


def isPP(n):
    for i in range(2, n):
        p = 2
        while i**p <= n:
            if i**p == n:
                return [i, p]
            p += 1
    return None