Algorithms to find gcd and to reduce fractions

euclideanalgorithm.py

import warnings

def warn(m,n):
    #If m,n are not integers, or are not less than 0, return a warning
    if type(m) != int or type(n) != int or m < 0 or n < 0:
        warnings.warn("Input was not a strictly positive integer")

def euclidean_division(m, n):
    #The Euclidean division algorithm takes two inputs, m and n in this case, and returns two values which represent
    #q and r such that, if m > n, m = qn + r, where 0 <= r < n.
    #We can assume WLOG that m, n > 0.
    warn(m,n)
    if m >= n:
        q = int(m/n)
        r = m - q*n
    else:
        q = int(n/m)
        r = n - q*m
    return (q,r)

def gcd(m, n):
    #This algorithm uses the Euclidean algorithm prior defined in order to find the greatest common divisor.
    #See: https://en.wikipedia.org/wiki/Euclidean_algorithm
    #We once again assume m,n > 0 WLOG.
    warn(m,n)
    ma = max(m,n)
    mi = min(m,n)
    q, r = euclidean_division(ma,mi)
    if r == 0:
        return mi
    else:
        return gcd(mi, r)

def reduce_fraction(numerator, denominator):
    #Takes two inputs, numerator and denominator, and returns the reduced fraction
    greatest = gcd(numerator, denominator)
    num = int(numerator/ greatest)
    den = int(denominator/greatest)
    return (num, den)