python事件驱动event实现详解

from time import sleep
def demo():
 print('BB')
while True:
 demo()
 sleep(1.0)

# -*- coding: utf-8 -*-
"""
Created on Tue Nov 13 13:51:31 2018

@author: 18665
"""
# 系统模块
from queue import Queue, Empty
from threading import *
########################################################################
class EventManager:
 #----------------------------------------------------------------------
 def __init__(self):
  """初始化事件管理器"""
  # 事件对象列表
  self.__eventQueue = Queue()
  # 事件管理器开关
  self.__active = False
  # 事件处理线程
  self.__thread = Thread(target = self.__Run)
  self.count = 0
  # 这里的__handlers是一个字典，用来保存对应的事件的响应函数
  # 其中每个键对应的值是一个列表，列表中保存了对该事件监听的响应函数，一对多
  self.__handlers = {}
 #----------------------------------------------------------------------
 def __Run(self):
  """引擎运行"""
  print('{}_run'.format(self.count))
  while self.__active == True:
   try:
    # 获取事件的阻塞时间设为1秒
    event = self.__eventQueue.get(block = True, timeout = 1) 
    self.__EventProcess(event)
   except Empty:
    pass
   self.count += 1
 #----------------------------------------------------------------------
 def __EventProcess(self, event):
  """处理事件"""
  print('{}_EventProcess'.format(self.count))
  # 检查是否存在对该事件进行监听的处理函数
  if event.type_ in self.__handlers:
   # 若存在，则按顺序将事件传递给处理函数执行
   for handler in self.__handlers[event.type_]:
    handler(event)
  self.count += 1
 #----------------------------------------------------------------------
 def Start(self):
  """启动"""
  print('{}_Start'.format(self.count))
  # 将事件管理器设为启动
  self.__active = True
  # 启动事件处理线程
  self.__thread.start()
  self.count += 1
 #----------------------------------------------------------------------
 def Stop(self):
  """停止"""
  print('{}_Stop'.format(self.count))
  # 将事件管理器设为停止
  self.__active = False
  # 等待事件处理线程退出
  self.__thread.join()
  self.count += 1
 #----------------------------------------------------------------------
 def AddEventListener(self, type_, handler):
  """绑定事件和监听器处理函数"""
  print('{}_AddEventListener'.format(self.count))
  # 尝试获取该事件类型对应的处理函数列表，若无则创建
  try:
   handlerList = self.__handlers[type_]
  except KeyError:
   handlerList = []
 self.__handlers[type_] = handlerList
  # 若要注册的处理器不在该事件的处理器列表中，则注册该事件
  if handler not in handlerList:
   handlerList.append(handler)
  print(self.__handlers)
  self.count += 1
 #----------------------------------------------------------------------
 def RemoveEventListener(self, type_, handler):
  """移除监听器的处理函数"""
  print('{}_RemoveEventListener'.format(self.count))
  try:
   handlerList = self.handlers[type_]
   # 如果该函数存在于列表中，则移除
   if handler in handlerList:
    handlerList.remove(handler)
   # 如果函数列表为空，则从引擎中移除该事件类型
   if not handlerList:
    del self.handlers[type_]
  except KeyError:
   pass
  self.count += 1
 #----------------------------------------------------------------------
 def SendEvent(self, event):
  """发送事件，向事件队列中存入事件"""
  print('{}_SendEvent'.format(self.count))
  self.__eventQueue.put(event)
  self.count += 1
########################################################################
"""事件对象"""
class Event:
 def __init__(self, type_=None):
  self.type_ = type_  # 事件类型
  self.dict = {}   # 字典用于保存具体的事件数据

# -*- coding: utf-8 -*-
"""
Created on Tue Nov 13 13:50:45 2018

@author: 18665
"""

# encoding: UTF-8
import sys
from datetime import datetime
from threading import *
#sys.path.append('D:\\works\\TestFile')
#print(sys.path)
from eventManager import *

#事件名称 新文章
EVENT_ARTICAL = "Event_Artical"

#事件源 公众号
class PublicAccounts:
 def __init__(self,eventManager):
  self.__eventManager = eventManager

 def WriteNewArtical(self):
  #事件对象，写了新文章
  event = Event(type_=EVENT_ARTICAL)
  event.dict["artical"] = u'如何写出更优雅的代码\n'
  
  #发送事件
  self.__eventManager.SendEvent(event)
  print(u'公众号发送新文章\n')

#监听器 订阅者
class Listener:
 def __init__(self,username):
  self.__username = username

 #监听器的处理函数 读文章
 def ReadArtical(self,event):
  print(u'%s 收到新文章' % self.__username)
  print(u'正在阅读新文章内容：%s' % event.dict["artical"])

"""测试函数"""
#--------------------------------------------------------------------
def test():
 # 实例化监听器
 listner1 = Listener("thinkroom") #订阅者1
 listner2 = Listener("steve")  #订阅者2
 # 实例化事件操作函数
 eventManager = EventManager()

 #绑定事件和监听器响应函数(新文章)
 eventManager.AddEventListener(EVENT_ARTICAL, listner1.ReadArtical)
 eventManager.AddEventListener(EVENT_ARTICAL, listner2.ReadArtical)
 # 启动事件管理器,# 启动事件处理线程
 eventManager.Start()

 publicAcc = PublicAccounts(eventManager)
 timer = Timer(2, publicAcc.WriteNewArtical)
 timer.start()

if __name__ == '__main__':
 test()