class Compute_number():
    """Compute class to compute

    """
    def __init__(self):
        """initialize
        """
        return self
    def sum(self,a,b):
        """SUM

        Args:
            a: first argument
            b: second argument

        Returns: sum of a and b

        """
        self.a= a
        self.b = b
        return a +b

    def diff(self, a,b):
        """ difference of the values
        Args:
            a: first arg
            b: second arg

        Returns: a-b

        """
        return a-b
