Question

So say I have this graph

class Graph:
    def __init__(self):
        self.nodes =[]
        self.edges = {}

    def add_node(self,value):
        self.nodes.append(value)

    def is_node_present(self,node):
        return True if node in self.nodes else False

Now what I want to do is something have user interact with this class..
Something like:

> g = Graph()
 query executed
> g.add_node(2)
  query executed
>g.is_node_present(2)
  True

You know something like this.. (until user presses some secret button to quit)

How do i do this in python
Thanks

Answer 1

You want to look at http://docs.python.org/2/library/cmd.html as it handles the processing loop etc.

Dough Hellman http://www.doughellmann.com/PyMOTW/cmd/ is always a great resource of examples.

From Dough

import cmd

class HelloWorld(cmd.Cmd):
    """Simple command processor example."""

    def do_greet(self, person):
        """greet [person]
        Greet the named person"""
        if person:
            print "hi,", person
        else:
            print 'hi'

    def do_EOF(self, line):
        return True

    def postloop(self):
        print

if __name__ == '__main__':
    HelloWorld().cmdloop()

Example

$ python cmd_arguments.py
(Cmd) help

Documented commands (type help ):
========================================
greet

Undocumented commands:
======================
EOF  help

(Cmd) help greet
greet [person]
        Greet the named person

Again all from Dough Hellman 😀