mit 6.0001 - define Fraction class and methods

fraction_class.py

class Fraction(object):
  def __init__(self, num, den):
    assert type(num) == int and type(den) == int and den != 0
    self.num = num
    self.den = den
  
  def __str__(self):
    return self.num + "/" + self.den

  def __add__(self, other):
    num_add = self.num*other.den + self.den*other.num
    den_add = self.den*other.den
    return Fraction(num_add, den_add)
  
  def __float__(self):
    return self.num/self.den #dividing two ints yields a float
  
  def inverse(self):
    return Fraction(self.den, self.num)

a = Fraction(1, 4)
b = Fraction(3, 4)
c = a + b
print(float(c))
print(Fraction.__float__(c))
print(float(b.inverse()))