python multiprocessing Pool with map_async -

i trying use multiprocessing package in python pool.

i have function f called map_async function:

from multiprocessing import pool  def f(host, x):     print host     print x  hosts = ['1.1.1.1', '2.2.2.2'] pool = pool(processes=5) pool.map_async(f,hosts,"test") pool.close() pool.join() 

this code has next error:

traceback (most recent call last):   file "pool-test.py", line 9, in <module>     pool.map_async(f,hosts,"test")   file "/usr/lib/python2.7/multiprocessing/pool.py", line 290, in map_async     result = mapresult(self._cache, chunksize, len(iterable), callback)   file "/usr/lib/python2.7/multiprocessing/pool.py", line 557, in __init__     self._number_left = length//chunksize + bool(length % chunksize) typeerror: unsupported operand type(s) //: 'int' , 'str' 

i don't know how pass more 1 argument f function. there way?

"test" interpreted map_async's chunksize keyword argument (see the docs).

your code should (here copy-pasted ipython session) :

from multiprocessing import pool  def f(arg):     host, x = arg     print host     print x  hosts = ['1.1.1.1', '2.2.2.2'] args = ((host, "test") host in hosts) pool = pool(processes=5) pool.map_async(f, args) pool.close() pool.join() ## -- end pasted text --  1.1.1.1 test 2.2.2.2 test 

note: in python 3 can use starmap, unpack arguments tuples. you'll able avoid doing host, x = arg explicitely.