Web Dev with Python Flask

1. Web Development with Python
Flask
Integrative Programming Module
Lessons 1–6 + Cheatsheets

2. Lesson 1: Introduction to Flask
• Definition: Flask is a lightweight Python web
framework.
• Install: pip install flask
• Hello World Example:
• from flask import Flask
• app = Flask(__name__)
• @app.route('/')
• def home(): return 'Hello, World!'
• app.run(debug=True)

3. Lesson 2: Templates & Jinja
• Use Jinja2 templates to embed Python in
HTML.
• Project structure: templates/ folder.
• base.html + index.html
• render_template('index.html', var=value)
• {{ var }} → prints variable
• {% block content %}{% endblock %} → layout
inheritance

4. Lesson 3: Forms & User Input
• HTML forms send data via GET or POST.
• Flask handles input with request.form.
• Example:
• @app.route('/', methods=['GET','POST'])
• if request.method == 'POST':
• name = request.form['name']
• return f'Hello {name}'

5. Lesson 4: Database Integration
• SQLite built-in with Python.
• Steps: connect, cursor, execute SQL, commit,
close.
• Example:
• conn = sqlite3.connect('db.db')
• c.execute('CREATE TABLE students ...')
• INSERT / SELECT / UPDATE / DELETE

6. Lesson 5: CRUD System
• CRUD = Create, Read, Update, Delete.
• Routes:
• • Create → POST form insert
• • Read → SELECT and display list
• • Update → form + SQL UPDATE
• • Delete → route with SQL DELETE

7. Lesson 6: Final Project
• Build a small CRUD system:
• Examples: Student Records, Inventory, Contact
Book.
• Requirements:
• • Flask + SQLite
• • CRUD complete
• • Documentation (ERD, Use Case, screenshots)
• • Group demo & defense

8. Flask Cheatsheet
• Flask Route Skeleton:
• @app.route('/path', methods=['GET','POST'])
• def func(): return render_template('file.html')
• Jinja:
• {{ var }}, {% if ... %}, {% for ... %}
• {% extends 'base.html' %}, {% block content %}
• SQL CRUD: