finding GCD in python

GCD.py

class GCD(object):

    def __init__(self):
        pass

    def gen(self, first, second):
        self.first = first
        self.second = second
        if(first > second):
            self.result()
            x = 0
            while x <= first and x <= second:
                x += 1
                if(first % x and second % x == 0):
                    gcd = x
            if(second == 0):
                gcd = first
                # self.result()
                return gcd

            else:
                return self.gen(second, first % second)
        else:
            print("ERROR: The First integer has to be greater than second one.")
            pass

    def result(self):
        s = 'E[{0},{1}]'.format(self.first, self.second)
        print(s)