Suppress output in multiprocessing process

Question

I have some code which runs in parallel using the multiprocessing Pool class. Unfortunately some of the functions I use from another library have some verbose output. To abstract the problem have a look at the following example:

from multiprocessing import Pool def f(x): print 'hello' return x*x p = Pool(10) p.map(f, [1,2,3])

So this will print 'hello' like 10 times. Is there a possibility to mute the output of the processes or to put the std.out in some variable? Thanks for any suggestion.

EDIT: I don't want to redirect the whole stdout, just for the processes of my pool.

It doesn't work I think the problem is that multiple independent processes are spawned. — jrsm
– jrsm, Commented Jun 14, 2015 at 13:36

unutbu · Accepted Answer · 2015-06-14 13:44:03Z

Use the initializer parameter to call mute in the worker processes:

import sys import os from multiprocessing import Pool def mute(): sys.stdout = open(os.devnull, 'w') def f(x): print 'hello' return x*x if __name__ == '__main__': p = Pool(10, initializer=mute) p.map(f, [1,2,3]) print('Hello')

prints

Hello

Collectives™ on Stack Overflow

Suppress output in multiprocessing process

1 Answer 1

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Linked

Related