[Python-Dev] multiprocessing not compatible with functional.partial

[Christian Heimes]

Neal Becker schrieb:
> If the argument to pool.map (f, args)
> is
> f = functional.partial (my_func, some_keyword_arg=whatever)
> 
> I get:
> 
> Traceback (most recent call last):
>   File "/usr/lib/python2.5/site-packages/multiprocessing-2.6.1.1-py2.5-linux-
>     self.run()
>   File "/usr/lib/python2.5/site-packages/multiprocessing-2.6.1.1-py2.5-linux-
>     self._target(*self._args, **self._kwargs)
>   File "/usr/lib/python2.5/site-packages/multiprocessing-2.6.1.1-py2.5-linux-
>     task = get()
>   File "/usr/lib/python2.5/site-packages/multiprocessing-2.6.1.1-py2.5-linux-
>     return recv()
> TypeError: type 'partial' takes at least one argument

functool.partial instances are not picklable. You have to teach
multiprocessing how to serialize a functool.partial instance.

Christian