python interactive shell using cmd repeating statements with no arguments typed
Question: New to python and i'm working on an interactive shell using cmd that takes
defined functions and arguments and returns value in an if/then format.
Example below. But my issue is that every time the user types a function and i
return something to the user, if they just hit enter then they recieve the
last provided output.

For example code below...but basically if the user doesn't type an argument or
function for that matter, i just want nothing displayed just a "" or empty
space. I assumed the else pass argument would have done that for me, but
obviously not. I have tried if and elif, with the same results.

Example output with "test arp", just hitting enter returns the previous
argument pressed :

    
    
    user@hostname>test arp
    ? (192.168.50.1) at 0:26:88:38:c6:48 on en0 ifscope [ethernet]
    ? (192.168.50.255) at ff:ff:ff:ff:ff:ff on en0 ifscope [ethernet]
    > **<enter key>**
    ? (192.168.50.1) at 0:26:88:38:c6:48 on en0 ifscope [ethernet]
    ? (192.168.50.255) at ff:ff:ff:ff:ff:ff on en0 ifscope [ethernet]
    > **<enter key>**
    

**_Example Code:_** #!/usr/bin/env python

    
    
    from cmd import Cmd
    from time import ctime
    import csv, os, subprocess, getpass, socket, pwd, re, select, shutil, subprocess, sys
    
    syntaxError = "Sorry that syntax isn't quite right..."
    
    class cliPrompt(Cmd):
    
        def do_test(self, args):
            if len(args) == 0:
                print syntaxError  
            if args == '?':
                print 'want to read the help?'
            if args == 'arp':
                subprocess.call('arp -an', shell=True)
            if args == 'cpu':
                subprocess.call('grep "model name" /proc/cpuinfo', shell=True)
            if args == 'firewall':
                subprocess.call('iptables -L -v -n --line-numbers', shell=True)
            if args == 'interfaces':
                subprocess.call('ifconfig', shell=True)
            else: 
                pass                                            
    
    if __name__ == '__main__':
        prompt = cliPrompt()
        prompt.prompt = '>'
        prompt.cmdloop()
    


Answer: Right on the front page of the cmd documentation discusses disabling the
returning previous command option.

<https://wiki.python.org/moin/CmdModule>

