How To Pass A List From Python By Jinja2 To Javascript

When working on web development projects, you often encounter the need to pass data seamlessly from Python to JavaScript. Luckily, with the powerful combination of Python and Jinja2, you can achieve this without breaking a sweat. In this article, we'll walk you through the process of passing a list from Python using Jinja2 to JavaScript.

Jinja2 is a popular templating engine for Python that allows you to create dynamic web pages by embedding Python code within HTML templates. By leveraging Jinja2, you can pass Python variables, including lists, to your frontend JavaScript code effortlessly.

To start, make sure you have Jinja2 installed in your Python environment. You can install it using pip by running the following command:

pip install Jinja2

Next, let's create a simple Flask web application to demonstrate how to pass a list from Python to JavaScript using Jinja2. Here's a basic Flask app structure:

from flask import Flask, render_template

app = Flask(__name__)

@app.route('/')
def index():
    my_list = [1, 2, 3, 4, 5]
    return render_template('index.html', my_list=my_list)

if __name__ == '__main__':
    app.run(debug=True)

In the example code above, we define a Flask route that renders an `index.html` template and passes a list named `my_list` containing some dummy data.

Now, let's create the `index.html` template that will utilize Jinja2 to pass the Python list to JavaScript:

<title>Python to JavaScript</title>


    <ul id="my-list">
        {% for item in my_list %}
            <li>{{ item }}</li>
        {% endfor %}
    </ul>

    
        var myList = {{ my_list | tojson }};
        console.log(myList);

In the `index.html` template, we iterate over the `my_list` using a Jinja2 loop and display each element within `