windows环境下multiprocessing报如下异常信息：

RuntimeError:

An attempt has been made to start a new process before the

current process has finished its bootstrapping phase.

This probably means that you are not using fork to start your

child processes and you have forgotten to use the proper idiom

in the main module:

if __name__ == '__main__':

freeze_support()

...

The "freeze_support()" line can be omitted if the program

is not going to be frozen to produce an executable.

解决办法：

在启进程的代码前面添加 if __name__ == "__main__":

代码如下：

import multiprocessing as mpimport osimport timedef th1():    print("this is th1,the time is {0}".format(time.ctime()))    #getppid获取父进程ID, getpid获取当前进程ID    print("th1",os.getppid(), "---", os.getpid())def setproc():    p1 = mp.Process(target = th1)    p1.start()    print("main", os.getppid(), "---", os.getpid())    if __name__ == "__main__":    #p1 = mp.Process(target = th1)    #p1.start()    setproc()    print("main end")