The Chatbot

A program that appears to hold a conversation — and is doing nothing of the kind. It hunts for keywords and serves canned replies from two tidy subprograms. This is not AI: there is no understanding anywhere in these 21 lines, which is exactly what makes it worth reading — see Automation and Artificial Intelligence for where the real thing differs, and Talk to the Machine for the class version of this game.

The program

def mentions(message, keyword):
    return keyword in message
 
def reply_to(message):
    if mentions(message, "homework"):
        return "Homework? I only know about sandwiches."
    elif mentions(message, "hello") or mentions(message, "hi"):
        return "Hello! Ask me anything. I know one thing."
    elif mentions(message, "sandwich"):
        return "Now we are talking. Peanut butter, obviously."
    elif mentions(message, "bye"):
        return "Goodbye! I will forget this instantly."
    else:
        return "Hmm. Try 'hello', 'sandwich', or 'homework'."
 
print("CHATTERBOT 1.0 - type 'bye' to leave")
 
message = ""
while not mentions(message, "bye"):
    message = input("You: ").lower()
    print("Bot:", reply_to(message))

Read it before you run it

Predict in writing first — then run the program and grade yourself.

• What does the bot say to I love HOMEWORK? Follow the .lower().
• Type this is fun and the bot says hello. Find the accidental hi — and say what that reveals about keyword matching.
• Trace exactly how typing goodbye ends the program. mentions is called in two different places — which one closes the loop?

Make it yours

1. One line. Rewrite any one reply in your own voice.
2. A few lines. Teach it a new keyword: one elif, one return.
3. A real change. Ask for the user’s name before the loop and weave it into every reply. Watch how much warmer the bot feels — while understanding precisely as little as before.

Curriculum connection

A1.3

develop computational artifacts for a variety of contexts and purposes that support the needs of diverse users and audiences

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C3.1

analyze existing code to understand the components and outcomes of the code

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C3.3

write subprograms, and use existing subprograms, to complete program components

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