[Pythonmac-SIG] opening an application from python

[altern]

hi

I am trying to launch a sound application (Pure Data) from a python 
program. For this I am using this code:
#
execdir = os.path.dirname(sys.argv[0])
pdexc = os.path.join(execdir, 
"/Pd-0.38-4-extended-RC1.app/Contents/MacOS/Pd")
arg = os.path.join(execdir, "audio.pd")
os.spawnl(os.P_NOWAIT, pdexc, arg)
# etc ...

i need to pass arguments to the application, PD is a command line 
application so it can be run from the terminal and several start up 
flags can be passed.

My problem is that it kind of runs but not properly. I get the process 
running, it is there if i do 'top' on the terminal. But the application 
never fully opens. I was wondering if there is some problem with doing 
this from Python, or if i should be using some other command.

thanks!

-- 
altern