Simple Python Chatbot

A simple rule-based chatbot built with Python. This project demonstrates how to use a JSON file to define conversational intents and a Python script to process user input and generate responses.

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Project Files

• intents.json
  The "brain" of the chatbot. This file contains a structured list of intents, which are categories of user messages. Each intent includes:

  • tag: A unique name for the intent (e.g., "greeting", "goodbye").
  • patterns: Example phrases a user might type that correspond to this intent.
  • responses: Possible replies the chatbot can give for this intent.

• chatbot.py
  The main Python script containing the chatbot logic. It loads the intents, processes user input, and selects an appropriate response.

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Code Overview

chatbot.py Structure

• Imports

  import json
  import random
  import re

  • json: Loads and parses the intents.json file.
  • random: Randomly selects a response from the list of possible responses for a given intent.
  • re: Uses regular expressions for robust word matching in user messages.

• SimpleChatbot Class

  • Encapsulates all chatbot functionality.

  • __init__(self, intents_path)
    Loads the intents from the specified JSON file.

  • _load_intents(self, filepath)
    Opens and loads the JSON file. Handles:

    • FileNotFoundError: If intents.json is missing.
    • json.JSONDecodeError: If the JSON file has a syntax error.

  • get_response(self, user_message)
    Processes user input:

    • Converts the message to lowercase and trims whitespace.
    • Iterates through each intent and its patterns.
    • Uses re.search() to check if a pattern exists as a whole word in the user's message (prevents partial matches, e.g., "hi" in "this").
    • If a match is found, selects a random response from the intent's responses.
    • If no match is found, returns a default "I don't understand" message.

• main() Function

  • Entry point for running the chatbot from the command line.
  • Creates a SimpleChatbot instance.
  • Prints a welcome message.
  • Enters a loop to continuously listen for user input.
  • If the user types "quit", the loop breaks and the program ends.
  • Otherwise, calls chatbot.get_response() and prints the bot's reply.

• if __name__ == "__main__":

  • Ensures the main() function runs only when the script is executed directly (not when imported as a module).

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How to Run the Project

1. Make sure you have both chatbot.py and intents.json in the same directory.

2. Open a terminal or command prompt.

3. Navigate to the directory where you saved the files.

4. Run the following command:

   python chatbot.py
   

5. Start chatting with the bot!
   Type quit to exit.

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