python设计模式第二十四天命令模式

Posted 2020-12-29 liuzhiqaingxyz

 1.使用场景

（1）调用过程比较繁琐，需要封装

（2）调用参数需要进行处理封装

（3）需要添加额外的功能，例如，日志，缓存，操作记录等

2.代码实现

#!/usr/bin/env python
#! _*_ coding:UTF-8 _*_

from abc import ABCMeta, abstractmethod

class Receiver(object):
    ‘‘‘这时基本的类‘‘‘
    def __init__(self):
        pass

    def action_one(self):
        print "action one..."

    def action_two(self):
        print "action two..."


class Command(object):
    ‘‘‘这时命令抽象类‘‘‘
    def __init__(self, receiver):
        self.receiver = receiver

    @abstractmethod
    def execute(self):
        pass


class OneCommand(Command):

    def execute(self):
        self.receiver.action_one()


class TwoCommand(Command):

    def execute(self):
        self.receiver.action_two()


class Invoker(object):
    ‘‘‘这时最终调用目标‘‘‘
    def __init__(self):
        pass

    def createCommand(self, command):
        self.command = command
        return self.command

if __name__ == "__main__":
    receiver = Receiver()

    oneCommand = OneCommand(receiver)
    twoCommand = TwoCommand(receiver)

    invoker = Invoker()
    invoker.createCommand(oneCommand).execute()
    invoker.createCommand(twoCommand).execute()

结果：

/Users/liudaoqiang/PycharmProjects/numpy/venv/bin/python /Users/liudaoqiang/Project/python_project/day24_command/command_test.py
action one...
action two...

Process finished with exit code 0