[python]多线程类的实现，setDaemon守护线程，join阻塞

#对于io操作来说，多线程和多进程性能差别不大
#1.通过Thread类实例化

import time
import threading

def get_detail_html(url):
    print("get detail html started")
    time.sleep(2)
    print("get detail html end")


def get_detail_url(url):
    print("get detail url started")
    time.sleep(4)
    print("get detail url end")


#2. 通过集成Thread来实现多线程


class GetDetailHtml(threading.Thread):
    def __init__(self, name):
        super().__init__(name=name)

    def run(self):
        print("get detail html started")
        time.sleep(2)
        print("get detail html end")


class GetDetailUrl(threading.Thread):
    def __init__(self, name):
        super().__init__(name=name)

    def run(self):#重写这个方法，
        print("get detail url started")
        time.sleep(4)
        print("get detail url end")

if  __name__ == "__main__":
    thread1 = GetDetailHtml("get_detail_html")
    thread2 = GetDetailUrl("get_detail_url")
    start_time = time.time()
    #thread1.setDaemon(True) 必须在t.start()之前设置 守护，主进程结束，这个无论是否执行完，都跟着结束
    thread1.start()
    thread2.start()

    thread1.join()  #阻塞，必须这个线程完成了，主线程才往下走
    thread2.join()

    #当主线程退出的时候， 子线程kill掉
    print ("last time: {}".format(time.time()-start_time))