Python "jail" no output over xinetd

Question

I'm trying out an insecure Python "jail" I found somewhere, when I run it locally and and execute it, it works fine. However, when I create a xinetd service for it, I can netcat to it, it does seem to connect but I see no output what so ever. The python file is:

#!/usr/bin/python -u

from sys import modules
modules.clear()
del modules

_raw_input = raw_input
_BaseException = BaseException
_EOFError = EOFError

__builtins__.__dict__.clear()
__builtins__ = None

print 'Get a shell, if you can...'

while 1:
  try:
    d = {'x':None}
    exec 'x='+_raw_input()[:50] in d
    print 'Return Value:', d['x']
  except _EOFError, e:
    raise e
  except _BaseException, e:
    print 'Exception:', e

The xinetd file is:

service jail-hard
{
    disable         = no
    id              = jail-hard
    type            = unlisted
    wait            = no
    socket_type     = stream
    protocol        = tcp
    user            = root
    server          = /usr/bin/python
    server_args     = /home/jailuser/jail-hard.py
    port            = 51337
}

And I just simply connect with "nc ip-address port".

Update 1: When I break out the jail and type in any command such as 'ls -la', I do get the output. So it seems there's something wrong with the print statements?