class Fraction:
    def __init__(self, numerator, denominator):
        self.numerator = numerator
        self.denominator = denominator
        self.simplify()

        if self.denominator == 1:
            # convert self to int of value numerator

def simplify(self):
        div = gcd(self.numerator, self.denominator)
        self.numerator //= div
        self.denominator //= div

def convert(fraction):
    if fraction.denominator == 1:
        return fraction.numerator  # int
    else:
        return fraction            # Fraction


f = Fraction(3, 1)
f = convert(f)