Flask is a popular web framework for Python that allows developers to build web applications quickly and easily. Here is an explanation of each step involved in creating a Flask application:
Install Flask: The first step is to install Flask on your machine. You can do this by using the pip package manager, which is the standard for installing Python packages. Open your command prompt or terminal and enter the following command:
pip install flask. This will download and install Flask on your system.
Import Flask: Once Flask is installed, you need to import it into your Python script. At the beginning of your Python file, add the following line of code:
from flask import Flask. This imports the Flask module and makes it available for use in your application.
Create an instance of the Flask class: After importing Flask, you need to create an instance of the Flask class. This is done by adding the following line of code:
app = Flask(__name__). The
__name__argument is a special variable in Python that represents the current module. This line of code creates a new Flask application instance and assigns it to the variable
Define routes: Routes are used to map URLs to functions in your application. You can define routes using the
@app.routedecorator. For example, to define a route for the homepage of your application, you can add the following code:
return 'Hello, World!'
This code defines a route for the root URL ("/") and associates it with the
index function. When a user visits the root URL, the
index function will be called and it will return the string "Hello, World!".
- Run the application: To run your Flask application, you need to add the following line of code at the end of your Python file:
if __name__ == '__main__':
This code checks if the current module is the main module (i.e., the module being run directly) and if so, it starts the Flask development server. The development server listens for incoming requests and routes them to the appropriate functions in your application.
That's it! With these steps, you have a basic Flask application up and running. You can now start building your web application by adding more routes and functions to handle different URLs and requests. Flask provides many features and extensions that make it easy to build robust and scalable web applications.