subprocess troubles

[Tomas Pelka]

Hey all,

have a problem with following piece of code:

--------------------------------------------------
import subprocess

paattern = "python"
cmd = "/usr/bin/locate"
arg1 = " -i"
arg2 = " -d /var/www/books/mlocate.db"
arg3 = str(" " + pattern)

p1 = subprocess.Popen([cmd, arg1, arg2, arg3], shell=False, 
stdout=subprocess.PIPE, stderr=subprocess.PIPE)
(stdoutdata, stderrdata) = p1.communicate()

print p1.returncode
print "%s -- %s" % (stdoutdata, stderrdata)
--------------------------------------------------

But return code is always 1 and command do not return any result/error 
(stdoutdata, stderrdata are None). If I run this command 
(/usr/bin/locate -i -d /var/www/books/mlocate.db python) from standard 
shell everything goes fine.

Could you please give me an advice what I'm doing wrong?

Thanks
Cheers

-- 
Tom