Problem with multiprocessing

[Peter Otten]

tleeuwenburg at gmail.com wrote:

> I have a problem using multiprocessing in a simple way. I created a
> file, testmp.py, with the following contents:
> 
> ---------------------------------------------------
> import multiprocessing as mp
> 
> p = mp.Pool(5)
> 
> def f(x):
>   return x * x
> 
> print map(f, [1,2,3,4,5])
> print p.map(f, [1,2,3,4,5])
> 
> ----------------------------------------------------
> 
> I'm using 2.6 r26:66713, so not quite bleeding edge.
> 
> If I run 'python2.6 testmp.py' I get errors of exactly the kind
> mentioned on docs.python.org for when multiprocessing is run using the
> interactive interpreter. However, I'm obviously *not* running the
> interactive interpreter.
> 
> Any suggestions?

I'm too lazy to read the docs, so I just tinkered:

import multiprocessing as mp
import testmp

p = mp.Pool(5)

def f(x):
  return x * x

if __name__ == "__main__":
    print map(f, [1,2,3,4,5])
    print p.map(testmp.f, [1,2,3,4,5])