Are you interested in creating your own web application but unsure where to start? Look no further! In this comprehensive guide, we will walk you through the process of building your first web app using Flask, a powerful and beginner-friendly Python web framework. Flask enables you to develop web applications quickly and efficiently with minimal code. Let’s dive in and begin constructing your very own web app!
Checkout the video here – https://youtu.be/Vvf_mGajUUs
Step 0: Understanding Flask
Before we embark on this journey, let’s familiarize ourselves with Flask. Flask is a lightweight web framework written in Python. It offers essential tools and libraries for developing web applications, making it an excellent choice for beginners. Flask follows a “micro” design philosophy, prioritizing simplicity and extensibility, allowing you to add only the necessary features.
Step 1: Installing and Setting Up Flask
To get started, ensure that Python is installed on your computer. Once you have Python, installing Flask is a breeze using pip, the Python package installer. Open your terminal or command prompt and enter the following command:
pip install flask
This command will download and install Flask on your system.
Step 2: Create a directory to work in
With Flask installed, let’s create a new directory for your project.
Now create the following 2 things in the folder:
- A file called app.py. This file will serve as the entry point for your Flask application.
- A folder called templates
Step 3: Coding Your Flask Web App
app.py file, begin by importing the Flask module and creating a Flask instance:
from flask import Flask,render_template app = Flask(__name__) @app.route('/') def home(): return "Welcome to my Flask web app!"
Subsequently, define a route that corresponds to the root URL of your web app. This route will handle incoming requests to your application:
Congratulations! You have just established your first Flask route. When users visit the root URL of your web app, they will be greeted with the message, “Welcome to my Flask web app!”
Step 4: Running Your Web App
To run your web app, return to your terminal or command prompt, navigate to the directory where your
app.py file is located, and execute any of the following commands:
You should see output similar to the following:
Open your web browser and visit
http://127.0.0.1:5000/. You should now observe the message you defined in the
Step 5: Expanding Your Web App
Now that you have the basic structure of your web app, it’s time to enhance its functionality. Flask enables you to define additional routes and handle different URLs.
For instance, you can create a new route that displays an “About” page:
from flask import Flask,render_template app = Flask(__name__) @app.route('/') def home(): return "Welcome to my Flask web app!" @app.route('/about') def about(): return "This is my Flask web app!"
http://127.0.0.1:5000/about, users will encounter the message, “This is my Flask web app!”
Step 6: Templating and Styling
Flask supports templates, which allow you to separate the structure of your web app from its content. HTML templates enable the creation of dynamic web pages.
Within your project directory, create a new directory called
templates. Inside the
templates directory, create a new file named
index.html. Add the following content to
<!DOCTYPE html> <html> <head> <title>My Flask Web App</title> </head> <body> <h1>Welcome to my Flask web app!</h1> <p>This is a sample web page.</p> </body> </html>
app.py, import the
render_template function from Flask and update the
home() function to render the
from flask import Flask,render_template app = Flask(__name__) @app.route('/') def home(): return render_template('index.html') # return "Welcome to my Flask web app!" @app.route('/about') def about(): return "This is my Flask web app!"
Now, when users visit
http://127.0.0.1:5000/, they will see the content of the
Congratulations on successfully building your first web app using Flask! In this article, we guided you through the process of setting up Flask, constructing a basic web app, running the app, expanding its functionality, and implementing templates. With this solid foundation, we encourage you to explore Flask’s documentation and experiment with different features to enhance your web app further.
So in this way, you can create your first web app using Flask. Check out my Flask projects here.
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