python 多进程

#方法一 直接调用
import time
import random
from multiprocessing import Process
def run(name):
    index = 0
    for i in range(3):
        print('%s runing' %name)
        time.sleep(random.randrange(1,5))
        print('%s running end' %name)
        index +1

l = []
if __name__ == "__main__":
    for i in range(20):
        p = Process(target=run,args=(i,))
        p.start()
        l.append(p)
    for proc in l:
        proc.join()
    print("执行完毕")