Web Development with Python

Web Development with Python

Python is widely used for web development due to its simplicity, readability, and powerful frameworks. It supports both backend development and full-stack development.

1. Popular Python Web Frameworks

2. Setting Up a Web Project

Flask Example:

from flask import Flask, render_template

app = Flask(__name__)

@app.route('/')
def home():
    return "Hello, World!"

@app.route('/about')
def about():
    return "About Page"

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

• Run the app: python app.py

• Access in browser: http://127.0.0.1:5000/

Django Example:

# Install Django
pip install django

# Create a project
django-admin startproject mysite

# Start development server
python manage.py runserver

• Access in browser: http://127.0.0.1:8000/

• Create apps, models, views, and templates for functionality.

3. Routing

• Routes define URLs and their corresponding views.

• Flask: @app.route('/path')

• Django: path('path/', views.view_name) in urls.py

4. Templates

• Templates allow dynamic HTML rendering.

• Flask: Uses Jinja2

• Django: Uses Django Template Language

<!-- example.html -->
<h1>Hello, {{ name }}!</h1>

# Flask
from flask import render_template
@app.route('/hello/')
def hello(name):
    return render_template('example.html', name=name)

5. Forms and Input Handling

from flask import request

@app.route('/submit', methods=['POST'])
def submit():
    name = request.form['name']
    return f"Hello {name}"

• Django uses forms.py and request.POST for form handling.

6. Database Integration

• Python web frameworks support relational and NoSQL databases.

• Django has built-in ORM for SQLite, PostgreSQL, MySQL.

• Flask supports SQLAlchemy or other ORMs.

Flask + SQLAlchemy Example:

from flask_sqlalchemy import SQLAlchemy

app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///test.db'
db = SQLAlchemy(app)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(50))

7. REST APIs

• Use frameworks like Flask or FastAPI to create APIs.

Flask API Example:

from flask import jsonify

@app.route('/api/data')
def api_data():
    data = {"name": "Alice", "age": 25}
    return jsonify(data)

8. Key Points

• Python frameworks simplify backend development and API creation.

• Flask is lightweight; Django is full-featured.

• Use templates for dynamic HTML, ORM for database access.

• Python integrates well with frontend technologies (HTML, CSS, JavaScript).

• Ideal for rapid development, prototyping, and production-ready applications.