80 join方法

import os
import time
from multiprocessing import Process


def task(n, tag):
	print(f'{tag} start running!')
	time.sleep(n)
	print(f'{tag} is done!')


if __name__ == '__main__':
	p1 = Process(target=task, args=(3, '进程1'))
	p2 = Process(target=task, args=(4, '进程2'))
	p3 = Process(target=task, args=(5, '进程3'))

	# t_start = time.time()
	# p1.start()
	# p1.join()
	# p2.start()
	# p2.join()
	# p3.start()
	# p3.join()
	# t = (time.time()-t_start)
	# print(t)  # 12s运行结束

	t_start = time.time()
	p1.start()
	p2.start()
	p3.start()
	p2.join()
	p3.join()
	p1.join()
	time.sleep(10)
	print(time.time() - t_start)  # 5s运行结束

	print(f'主程序{os.getpid()}运行！')