A friend of mine is learning to program with Python and started making a simple text game. He hit on the novel, if impractical solution, of using a function for each room... but was writing them all explicitly. I decided to show him about first class functions and closures with this example here. It's very rough and based on his architecture for…

textgame.py

commands = ["look", "smell"]
def make_room(description, exits):
    def room(skip = False, command = ""):
        if not skip or command == "look":
            print description
            print "You can go: " + ",".join(exits.keys())
        if command in exits.keys():
            return rooms[exits[command]]
        if command and command not in commands:
            print "I don't understand that."    
        return room
    return room
 
def get_command():
    return raw_input("> ")
 
rooms = {}
rooms['forest'] = make_room("A deep dark forest.", {'east': 'shack'})
rooms['shack'] = make_room("A small shack.", {'west': 'forest'})
 
def main():
    room = rooms['forest']
    skip = True
    command = ""
    room(False,"")
    while 1:
        command = get_command()
        new_room = room(skip, command)
        if new_room != room:
            room = new_room
            room(False, "")
        else:
            skip = True
        if command == "quit":
            print "Bye."
            break
 
main()