Problem with plpython

I'm running PostgreSQL 8.3 with pl/python 8.3. I am getting a different
date/time format when executing the below examples. The results are the
same whether I use os.popen or os.system. In plpython, I run:
import os
cmd = 'ls -al /var/log/messages > /var/tmp/log'
x = os.popen(cmd)
for aline in x.readlines():
plpy.notice('aline = %s', aline)

and the contents of /var/tmp/log are "-rw-r----- 1 syslog adm 495523 Oct 30
11:52 /var/log/messages

When, within Python, I run:
>>> cmd = 'ls -al /var/log/messages > /var/tmp/log'
>>> x = os.popen(cmd)
>>> for aline in x.readlines():
... print aline

the contents of /var/tmp/log are "-rw-r----- 1 syslog adm 23591 2009-10-30
13:03 /var/log/messages

How, using plpython, can I get the output date/time in the same format as
when executing from within python itself?