proxy.py

"""
给特别消耗资源去复制的对象提供一个接口
"""

import time


class SalesManager:
    def talk(self):
        print("Sales Manager ready to talk")


class Proxy:
    def __init__(self):
        self.busy = "No"
        self.sales = None

    def talk(self):
        print("Proxy checking for Sales Manager availability")
        if self.busy == "No":
            self.sales = SalesManager()
            time.sleep(0.1)
            self.sales.talk()
        else:
            time.sleep(0.1)
            print("Sales Manager is busy")


class NoTalkProxy(Proxy):
    def talk(self):
        print("Proxy checking for Sales Manager availability")
        time.sleep(0.1)
        print(
            "This Sales Manager will not talk to you",
            "whether he/she is busy or not",
        )


if __name__ == "__main__":
    p = Proxy()
    p.talk()
    p.busy = "Yes"
    p.talk()
    p = NoTalkProxy()
    p.talk()
    p.busy = "Yes"
    p.talk()

##### OUTPUT #####
# Proxy checking for Sales Manager availability
# Sales Manager ready to talk
# Proxy checking for Sales Manager availability
# Sales Manager is busy
# Proxy checking for Sales Manager availability
# This Sales Manager will not talk to you whether he/she is busy or not
# Proxy checking for Sales Manager availability
# This Sales Manager will not talk to you whether he/she is busy or not