Python--多进程--01

multiprocess

import multiprocessing
import time
def worker_1(interval):
    print(' i am worker1')
	n=5
	while n>0:
		print(time.ctime())
		n-=1
		time.sleep(interval)

def worker_2(interval):
	print(' i am worker2')
    print(interval)
def worker_3(interval):
	print(' i am worker3')
    print()

if __name__=="__main__":
	p1=multiprocessing.Process(target=worker_1,args=(1,))
	p2=multiprocessing.Process(target=worker_2,args=(3,))
	p3=multiprocessing.Process(target=worker_3,args=(5,))
	p1.start()
	p2.start()
	p3.start()

stdout

i am worker1
Sun Jan  7 13:46:50 2018
 i am worker2
 i am worker3
Sun Jan  7 13:46:51 2018
Sun Jan  7 13:46:52 2018
Sun Jan  7 13:46:53 2018
Sun Jan  7 13:46:54 2018

AttributeError：module 'main' has no attribute 'spec'

• 在ipython解释器中运行以上脚本一直弹出这个问题，AttributeError
  
  查阅官方文档，In the remaining cases __main__.__spec__ is set to None, as the code used to populate
  
  the __main__ does not correspond directly with an importable module
  • interactive prompt
  • -c switch
  • running from stdin
  • running directly from a source or bytecode fil
• 猜想应该是IPython解释器运行时，__main__是一个特殊的import system，在IPython无法将多进程初始化为None值，事实证明，在pycharm中运行不存在这个问题