python 运算符重载__add__

print(1 + 2)
print("1" + "2")
#不同的类型用加法会有不同的解释

class Person(object):
    def __init__(self, num):
        self.num = num
    #运算符重载
    def __add__(self, other):
        return Person(self.num + other.num)
    def __str__(self):
        return "num = " + str(self.num)
per1 = Person(1)
per2 = Person(2)
print(per1 + per2)#per1 + per2 ==== per1.__add__(per2)
#print(per1.__add__(per2))
print(per1)
print(per2)