Practice ADT Using Python

# Euclid's algoithm
def gcd(m, n):
  while m % n != 0:
    oldm = m
    oldn = n

    m = oldn
    n = oldm % oldn
  return n

# ADT for number presenting in fraction form
class Fraction:
  # constructor
  def __init__(self, top, bottom):
    if not(isinstance(top, int)) or not(isinstance(bottom, int)):
      raise RuntimeError("Both numerator and denominator should be integers.")
    
    if bottom == 0:
      raise RuntimeError("Denominator can't be 0.")
    
    if bottom < 0:
      bottom *= -1
      top *= -1
      
    common = gcd(top, bottom)
    self.num = top//common
    self.den = bottom//common

  # override print()
  def __str__(self):
    return str(self.num)+"/"+str(self.den)
  
  # get numerator
  def getNum(self):
    return self.num
    
  # get denominator  
  def getDen(self):
    return self.den

  # add
  def __add__(self, otherfraction):
    newnum = self.num * otherfraction.den + self.den * otherfraction.num
    newden = self.den * otherfraction.den
    return Fraction(newnum, newden)

  # subtraction
  def __sub__(self, otherfraction):
    newnum = self.num * otherfraction.den - self.den * otherfraction.num
    newden = self.den * otherfraction.den
    return Fraction(newnum, newden)

  # multiplication
  def __mul__(self, otherfraction):
    newnum = self.num * otherfraction.num
    newden = self.den * otherfraction.den
    return Fraction(newnum, newden)

  # division
  def __truediv__(self, otherfraction):
    newnum = self.num * otherfraction.den
    newden = self.den * otherfraction.num
    return Fraction(newnum, newden)

  # check if equal
  def __eq__(self, otherfraction):
    firstnum = self.num * otherfraction.den
    secondnum = otherfraction.num * self.den
    return firstnum == secondnum

  # check if greater than
  def __gt__(self, otherfraction):
    return (self - otherfraction).getNum() > 0
  
  # check if greater than or equal
  def __ge__(self, otherfraction):
    return (self - otherfraction).getNum() >= 0
    
  # check if less than
  def __lt__(self, otherfraction):
    return (self - otherfraction).getNum() < 0  
  
  # check if less than or equal
  def __le__(self, otherfraction):
    return (self - otherfraction).getNum() <= 0  
    
  # check if not equal
  def __ne__(self, otherfraction):
    firstnum = self.num * otherfraction.den
    secondnum = otherfraction.num * self.den
    return firstnum != secondnum  

def main():
  x = Fraction(1, 0)
  y = Fraction(1, 2)
  print("Numirator of ", x, " => ", x.getNum())
  print("Denominator of ", x, " => ", x.getDen())
  print(x, " + ", y, " => ", x + y)
  print(x, " - ", y, " => ", x - y)
  print(x, " * ", y, " => ", x * y)
  print(x, " == ", y, " => ", x == y)
  print(x, " > ", y, " => ", x > y)
  print(x, " >= ", y, " => ", x >= y)
  print(x, " < ", y, " => ", x < y)
  print(x, " <= ", y, " => ", x <= y)
  print(x, " != ", y, " => ", x != y)

main()