Python multiprocessing misunderstandings...

Question

Hi, I am having trouble with the python multiprocessing module. I am using the Process() class to spawn a new process in order to utilize my second core. This second process loads a bunch of data into RAM and than waits patiently instead of consuming.

Anyway, I just wanted to see what that process printed with the "print" command; however I do not see anything that it prints; I only see what the parent process prints. Now this makes sense to me since they live in two different process. The second process doesn't spawn its own shell/standard output window, nor is its output sent to the parent; yet when this process crashs, it prints everything that my script told it to print plus the stack trace and error.

I am wondering if their is a simple way to send the child process' prints to the first or have it spawn a shell/standard output so that I may debug it. I know I could create a multiprocessing.Queue dedicated to transmitting prints to the parent so that it may print these to standard output; but I do not feel like doing this if a simpler solution exists.

P.S. multiprocessing is great, but like most modules, it needs more documentation!

Thx

Answer 1

Have you tried flushing stdout?

import sys
print "foo"
sys.stdout.flush()