“'模块'对象没有属性......”多处理错误

Question

我使用Python 2.7运行Windows 7。

我正在尝试使用multiprocessing模块运行基本的多处理代码来测试可用性。我见过类似的错误here和here，但下面的代码没有这些问题。

当我从Anaconda命令提示符或Spyder IDE Python控制台运行以下代码（或使用multiprocessing模块的任何代码）时，我收到以下错误消息。

当我在Spyder IDE iPython控制台中运行代码时，我没有收到错误，但是程序永远不会完成，并且从我的Windows Task Manager我可以看到python没有使用任何CPU，即使Spyder显示它仍在运行（控制台上方的红色方块为红色）。

import multiprocessing

def funSquare(num):
    return num ** 2

if __name__ == '__main__':
    pool = multiprocessing.Pool()
    results = pool.map(funSquare, range(10))
    print(results)

Process PoolWorker-1:
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'
Process PoolWorker-2:
Process PoolWorker-5:
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'
Process PoolWorker-4:
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'
Process PoolWorker-3:
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'
Process PoolWorker-6:
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'
Process PoolWorker-8:
Process PoolWorker-7:
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'
Process PoolWorker-9:
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'
Process PoolWorker-10:
Traceback (most recent call last):
  File "C:\Anaconda\lib\multiprocessing\process.py", line 258, in _bootstrap
    self.run()
  File "C:\Anaconda\lib\multiprocessing\process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Anaconda\lib\multiprocessing\pool.py", line 102, in worker
    task = get()
  File "C:\Anaconda\lib\multiprocessing\queues.py", line 376, in get
    return recv()
AttributeError: 'module' object has no attribute 'funSquare'

有人可以告诉我如何解决这个问题吗？如果需要更多细节，请告诉我。谢谢！

Answer 1

我正在运行python 3并且IDE在anaconda（windows）中是spyder所以我也得到了错误。但经过漫长的一天搜索，我得到了一些解决方案，它帮助我运行相同的代码我的Windows机器。这个网站帮助我找到了解决方案：

http://python.6.x6.nabble.com/Multiprocessing-Pool-woes-td5047050.html

因为我使用的是python 3，所以我改变了这个程序：

from types import FunctionType
import marshal

def _applicable(*args, **kwargs):
  name = kwargs['__pw_name']
  code = marshal.loads(kwargs['__pw_code'])
  gbls = globals() #gbls = marshal.loads(kwargs['__pw_gbls'])
  defs = marshal.loads(kwargs['__pw_defs'])
  clsr = marshal.loads(kwargs['__pw_clsr'])
  fdct = marshal.loads(kwargs['__pw_fdct'])
  func = FunctionType(code, gbls, name, defs, clsr)
  func.fdct = fdct
  del kwargs['__pw_name']
  del kwargs['__pw_code']
  del kwargs['__pw_defs']
  del kwargs['__pw_clsr']
  del kwargs['__pw_fdct']
  return func(*args, **kwargs)

def make_applicable(f, *args, **kwargs):
  if not isinstance(f, FunctionType): raise ValueError('argument must be a function')
  kwargs['__pw_name'] = f.__name__  # edited
  kwargs['__pw_code'] = marshal.dumps(f.__code__)   # edited
  kwargs['__pw_defs'] = marshal.dumps(f.__defaults__)  # edited
  kwargs['__pw_clsr'] = marshal.dumps(f.__closure__)  # edited
  kwargs['__pw_fdct'] = marshal.dumps(f.__dict__)   # edited
  return _applicable, args, kwargs

def _mappable(x):
  x,name,code,defs,clsr,fdct = x
  code = marshal.loads(code)
  gbls = globals() #gbls = marshal.loads(gbls)
  defs = marshal.loads(defs)
  clsr = marshal.loads(clsr)
  fdct = marshal.loads(fdct)
  func = FunctionType(code, gbls, name, defs, clsr)
  func.fdct = fdct
  return func(x)

def make_mappable(f, iterable):
  if not isinstance(f, FunctionType): raise ValueError('argument must be a function')
  name = f.__name__    # edited
  code = marshal.dumps(f.__code__)   # edited
  defs = marshal.dumps(f.__defaults__)  # edited
  clsr = marshal.dumps(f.__closure__)  # edited
  fdct = marshal.dumps(f.__dict__)  # edited
  return _mappable, ((i,name,code,defs,clsr,fdct) for i in iterable)

在此功能之后，上面的问题代码也改变了一点：

from multiprocessing import Pool
from poolable import make_applicable, make_mappable

def cube(x):
  return x**3

if __name__ == "__main__":
  pool    = Pool(processes=2)
  results = [pool.apply_async(*make_applicable(cube,x)) for x in range(1,7)]
  print([result.get(timeout=10) for result in results])

我得到了输出：

[1, 8, 27, 64, 125, 216]

我认为这篇文章可能对某些Windows用户有用。