MODULE 13: Web Development with Python

In Module 13, we explore how Python powers the internet. Python is a top choice for back-end development because of its security, scalability, and the speed at which you can go from an idea to a live website.

1. Introduction to Web Frameworks

A web framework is a collection of tools and libraries that handle the “boring” parts of web development (like handling database connections or routing URLs) so you can focus on building your app.

• Micro-frameworks: Lightweight and flexible (e.g., Flask, FastAPI).
• Full-stack frameworks: “Batteries-included” with everything pre-configured (e.g., Django).

2. Flask Basics

Flask is a minimalist “micro” framework. It is easy to learn and gives you total control over which components to use.

Example:

Python

from flask import Flask
app = Flask(__name__)

@app.route("/")
def home():
    return "Welcome to my Flask Site!"

if __name__ == "__main__":
    app.run()

3. Django Basics

Django is a high-level framework that encourages rapid development. It comes with a built-in admin panel, database ORM, and user authentication out of the box. It follows the MVT (Model-View-Template) architecture.

4. REST APIs

A REST API (Representational State Transfer) is a way for two computers to talk to each other over the web. It uses standard HTTP methods:

• GET: Retrieve data.
• POST: Create data.
• PUT: Update data.
• DELETE: Remove data.

5. FastAPI Introduction

FastAPI is a modern framework designed for building APIs. It is incredibly fast (approaching Go and Node.js speeds) and automatically generates interactive documentation (Swagger UI) for your API.

Example:

Python

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
async def root():
    return {"message": "Hello from FastAPI"}

6. Authentication & Authorization

• Authentication: Verifying who a user is (e.g., Logging in with a password or JWT token).
• Authorization: Verifying what a user is allowed to do (e.g., Is this user an Admin or a regular Guest?).

7. API Testing (Postman)

Postman is a popular tool used to test APIs without having to build a front-end website. Developers use it to send requests to their Python servers and check if the JSON responses are correct.