Answer the door! A quick gist to show how a computer program would walk through the process of answering the door as if it were human.

answer_door.py

def answer_door():
    print "The doorbell rings and you open the door"
    print "Is this someone that you know?"
    answer = raw_input("Answer Yes No or Sketchy.").lower()
    if answer == "yes":
        print "Hey friend! How's it going? It's so great to see you again!"
    elif answer == "no":
        print "Oh, hello I do not think we've met before. How can I help you?"
    else:
        print "It's probably a bill collector! Shut the door!"
answer_door()