更改socket obj的\uqiu class\uu属性时发生类型错误

Question

以下是服务器代码（我正在定义一个从socket继承的类，并尝试使用该类在客户端套接字上调用send方法）：

import socket

class LogSocket(socket.socket):
    def send(self, data):
        print("Sending {0} to {1}".format(
            data, self.getpeername()[0]))
        super().send(data)

def respond(client):
    response = input("Enter a value: ")
    client.send(bytes(response, 'utf8'))
    client.close()

server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind(('',2401))
server.listen(1)
try:
    while True:
        client, addr = server.accept()
        client.__class__ = LogSocket
        respond(client)
finally:
    server.close()

客户代码是：

^{pr2}$

当我运行上述代码时，服务器崩溃并出现错误：

Traceback (most recent call last):
  File "10_04_server.py", line 20, in <module>
    client.__class__ = LogSocket
TypeError: __class__ assignment: 'LogSocket' object layout differs from 'socket'

这个错误是什么意思？为什么会发生？在

Answer 1

将__slots__属性设置为()，这将起作用：

class LogSocket(socket.socket):
    __slots__ = ()
    def send(self, data):
        print("Sending {0} to {1}".format(
            data, self.getpeername()[0]))
        super().send(data)

relevant pieces of documentation是：

The action of a __slots__ declaration is limited to the class where it is defined. As a result, subclasses will have a __dict__ unless they also define __slots__ (which must only contain names of any additional slots).

以及

__class__ assignment works only if both classes have the same __slots__.