【Error解决实录】TypeError: object.__new__() takes exactly one argument (the type to instantiate)

原代码：

# -*- coding: utf-8 -*-
class Person(object):

    def __new__(cls, name, age):
        print('__new__ called.')
        return super(Person, cls).__new__(cls, name, age)

    def __init__(self, name, age):
        print('__init__ called.')
        self.name = name
        self.age = age

    def __str__(self):
        return '' % (self.name, self.age)

if __name__ == '__main__':
    name = Person('xxx', 24)
    print(name)

期望输出：

__new__ called.
__init__ called.
<Person: xxx(24)>

实际输出：

报错原因：
上述为python2的写法，而博主用的是python3。

# __new__()修改前
return super(Person, cls).__new__(cls, name, age)
# __new__()修改后
return super(Person, cls).__new__(cls)

debug后:

# -*- coding: utf-8 -*-

class Person(object):

    def __new__(cls, name, age):
        print('__new__ called.')
        return super(Person, cls).__new__(cls)

    def __init__(self, name, age):
        print('__init__ called.')
        self.name = name
        self.age = age

    def __str__(self):
        return '' % (self.name, self.age)

if __name__ == '__main__':
    name = Person('xxx', 24)
    print(name)

__new__ called.
__init__ called.
<Person: xxx(24)>

总结：

1.创建一个类的顺序：先创建对象（__new__方法) 然后 初始化对象（__init__方法）
2.python2和python3对super函数不同的写法：python3__new__()不用参数。