python 在Python中简单实现事件驱动编程

Posted 2021-05-09

from friend import Friend

def main():
  myFriend = Friend("john")
  myFriend.name = "mike"


if __name__ == "__main__":
  main()

from event import ObjectWithEvents

class Friend(ObjectWithEvents):

    def __init__(self, name):
        self.__name = name
        self.addEvent("changed", self.welcome)

    @property
    def name(self):
        return self.__name

    @name.setter
    def name(self, value):
        if value:
          self.__name = value
          self.triggerEvent("changed")

    def welcome(self):
        print("Welcome, to a friend of mine", self.__name.title())

class ObjectWithEvents:
  
    callbacks = None
    
    def addEvent(self, eventname, callback):
        if self.callbacks is None:
            self.callbacks = {}
        if eventname not in self.callbacks:
            self.callbacks[eventname] = [callback]
        else:
            self.callbacks[eventname].append(callback)

    def triggerEvent(self, eventname):
        if self.callbacks is not None and eventname in self.callbacks:
            for callback in self.callbacks[eventname]:
                callback()