import threading,time
def run():time.sleep(3) #干活需要3sprint('哈哈哈')
#########################################
for i in range(5): #串行run()
#########################################
for i in range(5):  #并行，多线程， 就是N个线程一起在干活t = threading.Thread(target=run) #实例化了一个线程t.start()
#########################################

urls = {'besttest':'http://www.besttest.cn','niuniu':'http://www.nnzhp.cn','dsx':'http://www.imdsx.cn','cc':'http://www.cc-na.cn','alin':'http://limlhome.cn'
}

data= {}
def down_html(file_name,url):start_time = time.time()res = requests.get(url).contentopen(file_name+'.html','wb').write(res)end_time = time.time()run_time = end_time-start_timedata[url] = run_time

import requests,time,threading
data= {}
def down_html(file_name,url):start_time = time.time()res = requests.get(url).contentopen(file_name+'.html','wb').write(res)end_time = time.time()run_time = end_time-start_timedata[url] = run_time
threads = []
start_time = time.time()
for k,v in  urls.items():   #5次t = threading.Thread(target=down_html,args=(k,v)) #多线程的函数如果传参的话，必须得用argst.start()threads.append(t)
#6个线程
#进程里面默认有一个线程，这个线程叫做主线程
for t in threads:t.join()    #多线程等待，主线程循环等待5个子线程执行结束end_time = time.time()
run_time = end_time - start_time
print(data)
print('下载总共花了xxx时间',run_time)

import threading,time
def run():time.sleep(3)print('哈哈哈')for i in range(50):t = threading.Thread(target=run)t.setDaemon(True) #把子线程设置成为守护线程t.start()
print('Done,运行完成。')
#当主线程运行完成后就立即结束子线程。所以运行结果只输出了“Done,运行完成”。子线程并没有来得及打印“哈哈哈”就被结束了。

import threading,time
num = 1
lock = threading.Lock()  #申请一把锁def run():time.sleep(1)global numlock.acquire() #加锁num+=1lock.release() #解锁
ts = []
for i in range(100):t = threading.Thread(target=run)t.start()ts.append(t)
[t.join() for t in ts]   #列表生成式，多线程等待
print(num)

import multiprocessing,threading
def my():print('哈哈哈')def run(num):for i in range(num):   #启动num个线程t = threading.Thread(target=my)t.start()
if __name__ == '__main__':for i in range(5):   #启动5个进程p = multiprocessing.Process(target=run,args=(6,))  #启动一个进程，如果参数只有一个，那么参数后面一定要加一个逗号p.start()# 进程5个# 每个进程下启动6个线程
#进程等待也可以用pjoin()