Pathos multiprocessing pool CPickle error

问题

When i tried to run the following code:

from pathos.multiprocessing import ProcessingPool as Pool
list1 = [1,2,3,4,5]
list2 = [6,7,8,9,10]
def function1(x,y):
    print x
    print y
if __name__ == '__main__':
    pool = Pool(5)
    pool.map(function1, list1, list2)

It gets the followwing error:

Traceback (most recent call last):
  File "test.py", line 9, in <module>
    pool.map(function1, list1, list2)
  File "C:\Python27\lib\site-packages\pathos\multiprocessing.py", line 136, in map
    return _pool.map(star(f), zip(*args)) # chunksize
  File "C:\Python27\lib\site-packages\multiprocess\pool.py", line 251, in map
    return self.map_async(func, iterable, chunksize).get()
  File "C:\Python27\lib\site-packages\multiprocess\pool.py", line 567, in get
    raise self._value
cPickle.PicklingError: Can't pickle <type 'function'>: attribute lookup __builtin__.function failed

Isn't pathos.multiprocessing is designed to solve this problem?

回答1:

I'm the pathos author. When I try your code, I don't get an error. However, if you are seeing a CPickle.PicklingError, I'm guessing you have an issue with your install of multiprocess. You are on windows, so do you have a C compiler? You need one for multiprocess to get a full install of multiprocess.

来源：https://stackoverflow.com/questions/44094924/pathos-multiprocessing-pool-cpickle-error