TypeError:此构造函数不接受参数

Question

我对python很陌生，我试图创建一个基本的python计算器

#!/usr/bin/env python

class Calculator:
    def __int__(self,x,y):
        self.x = x
        self.y = y
    def add(self):
        return self.x + self.y
    def sub(self):
        return self.x - self.y
    def multi(self):
        return self.x * self.y
    def div(self):
        return self.x / self.y

    def convert(self,a,b):
        try:
            int_a = int(a)
            int_b = int(b)
        except ValueError:
            int_a = float(a)
            int_b = float(b)
        return int_a,int_b

run = True

while run:
    print "Please choose what you'd like to do:"
    print "0: Addition"
    print "1: Subtraction"
    print "2: Multiplication"
    print "3: Division"
    print "4: Quit Application"

    choice = raw_input()

    if choice == "0":
        str_a = raw_input("Enter 1st number : ")
        str_b = raw_input("Enter 2nd number : ")
        c = Calculator(str_a,str_b)
        c.add()

但我得到的错误如下：

  c = Calculator(str_a,str_b)
TypeError: this constructor takes no arguments

请任何人帮我解决这个问题