windows下面用multiprocess模块总是失败，为何

[JeanLove]

我在网上找到一些例子程序，基本都类似于：

from multiprocessing import Process
import time
def task(msg):
    print 'hello, %s' % msg
    time.sleep(1)

if __name__ == '__main__':
    p = Process(target=task, args=('world',))
    p.start()
    if p.is_alive():
        print 'Process: %s is running' % p.pid
    p.join()

我在我的win10+python2.7的环境下运行，总是报错：

python _.py
Traceback (most recent call last):
  File "_.py", line 2, in <module>
    from multiprocessing import Process
  File "D:\Documents\myrep\lang\py\multiprocessing.py", line 4, in <module>
    subprocess.call(['dir',],)
  File "C:\Python27\lib\subprocess.py", line 168, in call
    return Popen(*popenargs, **kwargs).wait()
  File "C:\Python27\lib\subprocess.py", line 390, in __init__
    errread, errwrite)
  File "C:\Python27\lib\subprocess.py", line 640, in _execute_child
    startupinfo)
WindowsError: [Error 2]

这是为什么呢，这个模块必须是linux吗？

[oyljerry]

对Windows支持不够好

[混沌鳄鱼]

改成这样

from multiprocessing import Process, freeze_support
import time
def task(msg):
    print 'hello, %s' % msg
    time.sleep(1)
 
if __name__ == '__main__':
    freeze_support()
    p = Process(target=task, args=('world',))
    p.start()
    if p.is_alive():
        print 'Process: %s is running' % p.pid
    p.join()

https://docs.python.org/2/library/multiprocessing.html?highlight=process#windows

[JeanLove]

引用 2 楼 xpresslink 的回复:

改成这样

from multiprocessing import Process, freeze_support
import time
def task(msg):
    print 'hello, %s' % msg
    time.sleep(1)
 
if __name__ == '__main__':
    freeze_support()
    p = Process(target=task, args=('world',))
    p.start()
    if p.is_alive():
        print 'Process: %s is running' % p.pid
    p.join()

https://docs.python.org/2/library/multiprocessing.html?highlight=process#windows

谢谢，这样确实可以了