How to Create a Chatbot using Python 3 with Source Code

Chatbots have become increasingly popular in recent years, serving a wide range of purposes from customer support to virtual assistants. Creating a chatbot using Python 3 is a great way to leverage the power of programming and natural language processing (NLP). In this article, we’ll walk you through the steps to create a simple chatbot using Python 3 and provide you with the complete source code.

Prerequisites

Before we dive into building our chatbot, make sure you have the following prerequisites:

Python 3: Ensure you have Python 3 installed on your computer. You can download it from the official website (https://www.python.org/downloads/).
Text Editor or IDE: You can use any text editor or integrated development environment (IDE) of your choice. Some popular options include Visual Studio Code, PyCharm, and Sublime Text.
Python Libraries: We will use the nltk library for natural language processing and numpy for mathematical operations. You can install these libraries using pip:

				
					pip install nltk numpy

Steps to Create a Chatbot

Now, let's get started with creating our chatbot:

Step 1: Import Libraries

In your Python script, start by importing the necessary libraries:

				
					import nltk
import numpy as np
import random
from nltk.stem import WordNetLemmatizer
from nltk.corpus import wordnet

Step 2: Prepare Data

You need to create a dataset of user inputs and corresponding bot responses. For simplicity, you can define a list of patterns and responses. Here's an example:

				
					patterns = [
    ["hi", "hello", "hey", "howdy"],
    ["how are you", "how is everything", "how's it going"],
    ["what's your name", "who are you", "are you human", "what can you do"],
    ["bye", "goodbye", "see you later"]
]

responses = [
    ["Hello!", "Hi there!", "Hey!", "Hi! How can I help you?"],
    ["I'm good. How can I assist you?", "Everything is fine. What can I do for you?"],
    ["I'm just a chatbot.", "I'm a bot designed to assist with tasks.", "I'm not human, but I can help you."],
    ["Goodbye!", "See you later!", "Take care!"]
]

Step 3: Preprocess Text

Define functions to preprocess user input and bot responses. We’ll use lemmatization to simplify words and make them more uniform.

				
					lemmatizer = WordNetLemmatizer()

def perform_lemmatization(text):
    words = nltk.word_tokenize(text)
    lemmatized_words = [lemmatizer.lemmatize(word.lower()) for word in words]
    return ' '.join(lemmatized_words)

Step 4: Create a Chat Function

Next, create a function to handle user input and generate responses:

				
					def chat():
    print("Chatbot: Hello! How can I assist you today?")
    while True:
        user_input = input("You: ")
        user_input = perform_lemmatization(user_input)

        for i, pattern_set in enumerate(patterns):
            for pattern in pattern_set:
                if pattern in user_input:
                    bot_response = random.choice(responses[i])
                    print("Chatbot:", bot_response)
                    break
            else:
                continue
            break

if __name__ == "__main__":
    chat()

Step 5: Run the Chatbot

Save your Python script with a .py extension and run it using your Python interpreter. You’ll see the chatbot in action, responding to user inputs based on the defined patterns and responses.

Conclusion

Creating a chatbot using Python 3 is a fun and educational project that introduces you to natural language processing and basic AI concepts. You can expand on this foundation by incorporating more advanced NLP techniques and integrating your chatbot into various applications. Experiment with different patterns and responses to make your chatbot more interactive and engaging. Happy coding!