多处理腌制错误：_pickle.PicklingError：无法腌制<function myprocess =“” at =“” 0x02b2d420 =“”>：它与__main __。myProcess

Question

我正在阅读和应用python书中的代码，并且不能在下面看到的简单示例中使用多重处理：

import multiprocessing


def myProcess():
    print("Currently Executing Child Process")
    print("This process has it's own instance of the GIL")
    print("Executing Main Process")
    print("Creating Child Process")


myProcess = multiprocessing.Process(target=myProcess)
myProcess.start()
myProcess.join()
print("Child Process has terminated, terminating main process")

我的平台是Windows 10 64位，并且在__name_ ==“ __main_”的情况下使用：在这种情况下不起作用。怎么了此代码应在python 3.5及更高版本中工作。我使用的Python版本是3.7。以下是完整的错误消息：

C:\Users\Xian\AppData\Local\Programs\Python\Python37-32\python.exe "C:/OneDrive/Utilizing sub-process.py"
Traceback (most recent call last):
  File "C:/OneDrive/Utilizing sub-process.py", line 25, in <module>
    myProcess.start()
  File "C:\Users\Xian\AppData\Local\Programs\Python\Python37-32\lib\multiprocessing\process.py", line 112, in start
    self._popen = self._Popen(self)
  File "C:\Users\Xian\AppData\Local\Programs\Python\Python37-32\lib\multiprocessing\context.py", line 223, in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
  File "C:\Users\Xian\AppData\Local\Programs\Python\Python37-32\lib\multiprocessing\context.py", line 322, in _Popen
    return Popen(process_obj)
  File "C:\Users\Xian\AppData\Local\Programs\Python\Python37-32\lib\multiprocessing\popen_spawn_win32.py", line 65, in __init__
    reduction.dump(process_obj, to_child)
  File "C:\Users\Xian\AppData\Local\Programs\Python\Python37-32\lib\multiprocessing\reduction.py", line 60, in dump
    ForkingPickler(file, protocol).dump(obj)
_pickle.PicklingError: Can't pickle <function myProcess at 0x02B2D420>: it's not the same object as __main__.myProcess

Answer 1

试试这个

def test()
    import multiprocessing

    multiprocessing.set_start_method("fork")

    p = multiprocessing.Process(target=xxx)
    p.start()

python multiprocessing Contexts and start methods