1. Introduction
Flask is a popular web framework in Python that allows you to build web applications easily and quickly. One of the key features of Flask is its ability to render Jinja templates and pass template variables. In this article, we will explore how to use Flask to render Jinja templates and manipulate template variables.
2. Installing Flask
To get started, we need to install Flask. You can install it using pip, the Python package manager, by running the following command:
pip install Flask3. Creating a Flask Application
After installing Flask, we can start creating our Flask application. Create a new file called app.py and import the Flask module:
from flask import Flask, render_templateNext, create a Flask application object and define a route that renders a Jinja template:
app = Flask(__name__)
@app.route('/')
def home():
return render_template('index.html')
4. Creating a Jinja Template
Now let's create a Jinja template called index.html. In this template, we can include HTML markup as well as template variables using the double curly braces syntax:
-<!DOCTYPE html>
-<html>
-<head>
- -<title>Flask Jinja Template</title>
-</head>
-<body>
- -<h1>Hello, {{ name }}!</h1>
- -<p>The temperature is set to {{ temperature }}.</p>
-</body>
-</html>
5. Passing Template Variables
In order to pass template variables to the Jinja template, we need to modify the route function in our Flask application. We can do this by passing the variables as arguments to the render_template function:
@app.route('/')
def home():
name = "John"
temperature = 0.6
return render_template('index.html', name=name, temperature=temperature)
6. Rendering the Jinja Template
When the user visits the '/' route of our Flask application, the home function is called and the Jinja template is rendered. The template variables passed to the template are replaced with their respective values:
-<!DOCTYPE html>
-<html>
-<head>
- -<title>Flask Jinja Template</title>
-</head>
-<body>
- -<h1>Hello, John!</h1>
- -<p>The temperature is set to 0.6.</p>
-</body>
-</html>
7. Modifying Template Variables
We can easily modify the template variables in our Flask application. For example, if we want to change the value of the name variable, we can simply assign a new value to it:
@app.route('/')
def home():
name = "Alice"
temperature = 0.6
return render_template('index.html', name=name, temperature=temperature)
8. Conclusion
In this article, we have learned how to use Flask to render Jinja templates and pass template variables. We have seen how to create a Flask application, create a Jinja template, and pass template variables using the render_template function. We have also explored how to modify the template variables in our Flask application.
Flask's integration with Jinja templates makes it easy to create dynamic web pages with variable content. By manipulating template variables, we can customize the content of our web pages based on user input or other factors.
Flask is a powerful framework for building web applications, and understanding how to render Jinja templates and pass template variables is a key skill for any Flask developer.