問題描述
我不明白為什么這么簡單的代碼
I don't understand why this simple code
# file: mp.py
from multiprocessing import Process
import sys
def func(x):
print 'works ', x + 2
sys.stdout.flush()
p = Process(target= func, args= (2, ))
p.start()
p.join()
p.terminate()
print 'done'
sys.stdout.flush()
連續創建pythonw.exe"進程并且它不打印任何東西，即使我從命令行運行它:
creates "pythonw.exe" processes continuously and it doesn't print anything, even though I run it from the command line:
python mp.py
我在 32 位和 64 位的 Windows 7 上運行最新的 Python 2.6
I am running the latest of Python 2.6 on Windows 7 both 32 and 64 bits
推薦答案
你需要保護然后使用 if __name__ == '__main__': 進入程序的入口點.
You need to protect then entry point of the program by using if __name__ == '__main__':.
這是一個特定于 Windows 的問題.在 Windows 上，您的模塊必須導入新的 Python 解釋器才能訪問您的目標代碼.如果你不停止這個新的解釋器運行啟動代碼，它將產生另一個孩子，然后再產生另一個孩子，直到它的 pythonw.exe 進程一目了然.
This is a Windows specific problem. On Windows your module has to be imported into a new Python interpreter in order for it to access your target code. If you don't stop this new interpreter running the start up code it will spawn another child, which will then spawn another child, until it's pythonw.exe processes as far as the eye can see.
其他平臺使用os.fork() 啟動子進程，所以不存在重新導入模塊的問題.
Other platforms use os.fork() to launch the subprocesses so don't have the problem of reimporting the module.
所以您的代碼需要如下所示:
So your code will need to look like this:
from multiprocessing import Process
import sys
def func(x):
print 'works ', x + 2
sys.stdout.flush()
if __name__ == '__main__':
p = Process(target= func, args= (2, ))
p.start()
p.join()
p.terminate()
print 'done'
sys.stdout.flush()
這篇關于Python 多處理不斷產生 pythonw.exe 進程而不做任何實際工作的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！