A builder design pattern or chaining in Python

FuncChanining.py

class Calculator:
    total = 0

    def add(self, number):
        self.total = self.total + number
        return self

    def remove(self, number):
        self.total = self.total - number
        return self

    def calc(self):
        return self.total

A = Calculator().add(12).remove(3).calc()
print(A)