How do I manage multiple processes in Python?
<p>I have a simple (i hope) question:
my problems started when i wrote a GUI.
i cannot refresh the user interface while executing heavy computations.</p>

<p>-if i use threads there is the G.I.L. (not too slow but the gui freezes)</p>

<p>i tryed so many things that my last hope is starting a new process (and here the problem)</p>

<p>first of all:
-i never used processes before (it could be a semantic error)</p>

<p>-i don't know the limitations ( and exceptions ) of processes</p>

<p>-i am running with cpython 3.1.2 , on Mac os x v 10.6.8</p>

<p>here is an example (not the real code but the result is the same) of what i need to solve:</p>

<pre><code>from multiprocessing import *
def bob(q):
    print(q)
A=Process(target=bob,args=("something"))
A.start()
A.is_alive()
A.join()
</code></pre>

<p>and the output is:</p>

<pre><code>True
</code></pre>

<p>it doesn't print "something",so i guess it doesn't run the process,but "A.is_alive()" says it is running and when the interpreter arrives to "A.join()" it waits more or less forever</p>

<p>can someone explain me this?</p>
