from multiprocessing import Pool
import os
import time
def worker(num):
print("task <%s> is runing <%d>" % (os.getpid(), num))
time.sleep(2)
def main():
# 定义一个进程池，最大进程数3
po = Pool(3)
for i in range(0, 10):
# Pool().apply_async(要调用的目标，(传递给目标的参数元祖,))
# 每次循环将会用空闲出来的子进程去调用目标
po.apply_async(worker, args=(i,))
print("---start---")
# 关闭进程池，关闭后po不再接收新的请求
po.close()
# 等待po中所有子进程执行完毕，必须放在close语句之后
po.join()
print("---end---")
if __name__ == '__main__':
main()
