class FourCal:

    def __init__(self, first, second):

        self.first = first

        self.second = second

    def setdata(self, first, second):

        self.first = first

        self.second = second

    def add(self):

        result = self.first + self.second

    def sub(self):

        result = self.first - self.second

        return result

    def mul(self):

        result = self.first * self.second

        return result

    def div(self):

        result = self.first / self.second

        return result

 

a = FourCal()