Build a Chatbot with Python: (Series – Part1)
Tags: javascript, python, programming, tutorial
Published: 2023-02-07 04:11:39


<h3 class="graf graf--h3 graf--empty"></h3>
<p class="graf graf--p">Chatbots have become increasingly popular in recent years, providing a convenient and accessible way for users to interact with technology.</p>
<p class="graf graf--p">In this article, we’ll explore the first three steps of building a chatbot with Python: installing required packages, importing the packages, and defining a function for responding to user input.</p>
<p class="graf graf--p">By the end of this article, you’ll have a solid foundation for building a functional chatbot that can respond to user input.</p>

<h4 class="graf graf--h3">Prerequisite</h4>
<ol class="postList">
 	<li class="graf graf--li">Basic understanding of Python programming language</li>
 	<li class="graf graf--li">Knowledge of using the command line or terminal</li>
 	<li class="graf graf--li">Familiarity with installing packages using the pip package manager</li>
 	<li class="graf graf--li">Access to a computer with Python installed</li>
 	<li class="graf graf--li">An IDE or text editor to write and run your Python code (<a class="markup--anchor markup--li-anchor" href="https://www.jetbrains.com/pycharm/download/#section=mac" target="_blank" rel="noreferrer nofollow noopener" data-href="https://www.jetbrains.com/pycharm/download/#section=mac">pycharm</a>, <a class="markup--anchor markup--li-anchor" href="https://code.visualstudio.com/Download" target="_blank" rel="noreferrer nofollow noopener" data-href="https://code.visualstudio.com/Download">Vs Code</a>)</li>
</ol>
<h4 class="graf graf--h3">Install the Required Packages</h4>
<p class="graf graf--p">The first step in building a Python chatbot is installing the necessary packages. Many packages are available for building chatbots in Python, including ChatterBot and NLTK.</p>
<p class="graf graf--p">This article will use ChatterBot, a popular open-source chatbot framework.</p>
<p class="graf graf--p">To install ChatterBot, you’ll need to open a terminal window and run the following command:</p>

<pre class="graf graf--pre graf--preV2" spellcheck="false" data-code-block-mode="1" data-code-block-lang="typescript"><span class="pre--content">pip install chatterbot</span></pre>
<p class="graf graf--p">Once the installation is complete, you’re ready to move on to the next step.</p>

<h4 class="graf graf--h3">Import the Packages</h4>
<p class="graf graf--p">Once you have installed the necessary packages, you’ll need to import them into your Python script. To do this, you’ll add the following lines of code to the top of your script:</p>

<pre class="graf graf--pre graf--preV2" spellcheck="false" data-code-block-mode="1" data-code-block-lang="javascript"><span class="pre--content"><span class="hljs-keyword">from</span> chatterbot <span class="hljs-keyword">import</span> <span class="hljs-title class_">ChatBot</span>
<span class="hljs-keyword">from</span> chatterbot.<span class="hljs-property">trainers</span> <span class="hljs-keyword">import</span> <span class="hljs-title class_">ChatterBotCorpusTrainer</span></span></pre>
<p class="graf graf--p">These lines import the ChatBot and ChatterBotCorpusTrainer classes from the ChatterBot library, which you’ll use to build and train your chatbot.</p>

<h4 class="graf graf--h3">Define a Function for Responding to User Input</h4>
<p class="graf graf--p">Once you have imported the necessary packages, you can start building your chatbot. The first step is to define a function that takes user input as an argument and returns a response.</p>
<p class="graf graf--p">To do this, you’ll add the following code to your script:</p>

<pre class="graf graf--pre graf--preV2" spellcheck="false" data-code-block-mode="1" data-code-block-lang="python"><span class="pre--content">
<span class="hljs-keyword">def</span> <span class="hljs-title function_">get_response</span>(<span class="hljs-params">user_input</span>):
    chatbot = ChatBot(
        <span class="hljs-string">'My Chatbot'</span>,
        logic_adapters=[
            {
                <span class="hljs-string">'import_path'</span>: <span class="hljs-string">'chatterbot.logic.BestMatch'</span>,
                <span class="hljs-string">'statement_comparison_function'</span>: <span class="hljs-string">'chatterbot.comparisons.levenshtein_distance'</span>,
                <span class="hljs-string">'response_selection_method'</span>: <span class="hljs-string">'chatterbot.response_selection.get_most_frequent_response'</span>
            }
        ]
    )

    response = chatbot.get_response(user_input)
    <span class="hljs-keyword">return</span> response</span></pre>
<p class="graf graf--p">In this code, you define a function called <strong class="markup--strong markup--p-strong">get_response</strong> that creates a new instance of the ChatBot class and sets its name to <strong class="markup--strong markup--p-strong">‘My Chatbot’</strong>.</p>
<p class="graf graf--p">You also set the <strong class="markup--strong markup--p-strong">logic_adapters</strong> argument to use the BestMatch adapter and set the <strong class="markup--strong markup--p-strong">statement_comparison_function</strong> to use the Levenshtein distance for comparison and the <strong class="markup--strong markup--p-strong">response_selection_method</strong> to use the most frequent response.</p>
<p class="graf graf--p">Use the <strong class="markup--strong markup--p-strong">get_response</strong> method of the ChatBot class to generate a response based on the user’s input, which you return as the result of the function.</p>

<h4 class="graf graf--h3">What is Levenshtein’s distance?</h4>
<p class="graf graf--p">The Levenshtein distance is a measure of the difference between two strings. It is also known as the “edit distance” between two strings.</p>
<p class="graf graf--p">It represents the minimum number of single-character edits (insertions, deletions, or substitutions) required to change one string into another.</p>
<p class="graf graf--p">For example, the Levenshtein distance between the words “dog” and “cat” is 3, as it would take 3 operations (2 deletions and 1 substitution) to change one into the other. On the other hand, the Levenshtein distance between the words “dog” and “dogs” is 1, as it would take only 1 operation (1 insertion) to change one into the other.</p>
<p class="graf graf--p">In building a chatbot, the Levenshtein distance can be used as a comparison function to determine the similarity between user input and a set of pre-defined statements.</p>
<p class="graf graf--p">By comparing the Levenshtein distance between the user input and each statement, the chatbot can select the most similar statement to the user input and generate a response based on that statement.</p>
<p class="graf graf--p">Next session, our focus will be on the following:</p>
<p class="graf graf--p"><strong class="markup--strong markup--p-strong">Implement a Natural Language Processing (NLP) Technique: Use an NLP technique such as keyword matching, conditional statements, or machine learning algorithms to generate responses based on the user’s input.</strong></p>
<p class="graf graf--p">To prepare for the next session, check out the following resources.</p>

<h4 class="graf graf--h3">Resources</h4>
<p class="graf graf--p"><a class="markup--anchor markup--p-anchor" href="https://www.nltk.org/book/" target="_blank" rel="noreferrer nofollow noopener" data-href="https://www.nltk.org/book/">Natural Language Processing with Python</a></p>
<p class="graf graf--p"><a class="markup--anchor markup--p-anchor" href="https://spacy.io/usage/spacy-101" target="_blank" rel="noreferrer nofollow noopener" data-href="https://spacy.io/usage/spacy-101">Spacy 101: Everything you need to know</a></p>
<p class="graf graf--p"><a class="markup--anchor markup--p-anchor" href="https://www.oreilly.com/library/view/building-chatbots-with/9781788470940/" target="_blank" rel="noreferrer nofollow noopener" data-href="https://www.oreilly.com/library/view/building-chatbots-with/9781788470940/">Building Chatbots with Python</a></p>
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