Python hasattr,getattr,setattr,delattr

Posted 2021-01-17 Presley

#!/usr/bin/env python
# -*- coding:utf-8 -*-
# 作者:Presley
# 邮箱:[email protected]
# 时间:2018-11-04
# 反射使用
import sys
class WebServer(object):
    def __init__(self,host,port):
        self.host = host
        self.port = port
    def start(self):
        print("Server is starting...")
    def stop(self):
        print("Server is stopping...")
    def restart(self):
        self.stop()
        self.start()

def test_run(ins,name):
    print("running...",name,ins.host)

if __name__ == "__main__":
    server = WebServer("localhost",333)
    ‘‘‘#方法1
    # #print(sys.argv[1])
    # cmd_dic = {
    #     "start":server.start,
    #     "stop":server.stop
    # }
    # if sys.argv[1] in cmd_dic:
    #     cmd_dic[sys.argv[1]]()‘‘‘

#1、hasattr,getattr
    #方法二
    if hasattr(server,sys.argv[1]):
        func = getattr(server,sys.argv[1]) #获取server.start方法的内存地址
        func() #相当于server.start()

#2、setattr
    ‘‘‘
    setattr(server,"run",test_run) #给实例绑定一个test_run方法,方法名字叫run
    server.run(server,"wohaoshuai")#绑定的方法调用类中属性需要传入对象名称
    ‘‘‘
#3、delattr
    delattr(WebServer,"start")
    server.restart()#报错