How to let Pool.map take a lambda function

Question

I have the following function:

def copy_file(source_file, target_dir):
    pass

Now I would like to use multiprocessing to exe

Answer 1

Question is a bit old but if you are still use Python 2 my answer can be useful.

Trick is to use part of pathos project: multiprocess fork of multiprocessing. It get rid of annoying limitation of original multiprocess.

Installation: pip install multiprocess

Usage:

>>> from multiprocess import Pool
>>> p = Pool(4)
>>> print p.map(lambda x: (lambda y:y**2)(x) + x, xrange(10))
[0, 2, 6, 12, 20, 30, 42, 56, 72, 90]