Question

我正在浏览python中的Multiprocessing库的文档。

这是我想要运行的示例：

from multiprocessing import Pool

def f(x):
    return x*x

if __name__ == '__main__':
    with Pool(5) as p:
        print(p.map(f, [1, 2, 3]))

该示例来自以下链接：Multiprocessing Doc

运行上述程序时出现以下错误：

Process SpawnPoolWorker-1:
Traceback (most recent call last):
  File "C:\Python35\lib\multiprocessing\process.py", line 254, in _bootstrap
    self.run()
  File "C:\Python35\lib\multiprocessing\process.py", line 93, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Python35\lib\multiprocessing\pool.py", line 108, in worker
    task = get()
  File "C:\Python35\lib\multiprocessing\queues.py", line 345, in get
    return ForkingPickler.loads(res)
AttributeError: Can't get attribute 'f' on <module '__main__' (built-in)>
Process SpawnPoolWorker-3:
Traceback (most recent call last):
  File "C:\Python35\lib\multiprocessing\process.py", line 254, in _bootstrap
    self.run()
  File "C:\Python35\lib\multiprocessing\process.py", line 93, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Python35\lib\multiprocessing\pool.py", line 108, in worker
    task = get()
Process SpawnPoolWorker-5:
  File "C:\Python35\lib\multiprocessing\queues.py", line 345, in get
    return ForkingPickler.loads(res)
Traceback (most recent call last):
  File "C:\Python35\lib\multiprocessing\process.py", line 254, in _bootstrap
    self.run()
  File "C:\Python35\lib\multiprocessing\process.py", line 93, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Python35\lib\multiprocessing\pool.py", line 108, in worker
    task = get()
  File "C:\Python35\lib\multiprocessing\queues.py", line 345, in get
    return ForkingPickler.loads(res)
AttributeError: Can't get attribute 'f' on <module '__main__' (built-in)>
AttributeError: Can't get attribute 'f' on <module '__main__' (built-in)>

这个过程也没有结束。如果我尝试按Enter键，python崩溃但程序仍然打开。

请告诉我需要做些什么来解决这个问题。

Answer 1

Python多处理通过在单独的Python进程（即另一个解释器实例）中再次加载程序来工作。

您正尝试直接使用REPL中的multiprocessing，输入代码，但这些代码无法正常工作，因为没有其他进程可以加载的文件。

您需要将代码存储在文件中。

多处理示例未提供所需的输出python3

1 个答案: