from multiprocessing import Process
import os
def run(name):
print 'The child process '%s' (pid %d) is running' % (name, os.getpid())
return
print 'The parent process(pid %d) is running' % os.getpid()
p = Process(target=run, args = ('test', ))
print 'The child process is ready to run!'
p.start();
p.join();
print 'The child process ends!'
这段程序运行就会提示错误
"Attempt to start a new process before the current process
has finished its bootstrapping phase."
这是 Windows 上多进程的实现问题。在 Windows 上,子进程会自动 import 启动它的这个文件,而在 import 的时候是会执行这些语句的。如果你这么写的话就会无限递归创建子进程报错。所以必须把创建子进程的部分用那个 if 判断保护起来,import 的时候 __name__ 不是 __main__ ,就不会递归运行了。