🚀 Study Flask - Your First Web Server

A progressive learning repository for students to master Flask basics step-by-step.

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📖 What is Flask?

Flask is a micro-framework for Python. Think of it as a toolbox that provides just the essentials to build a website. Unlike static HTML, Flask allows you to:

• Create dynamic web pages
• Use Python logic in your HTML (via Jinja2 templates)
• Handle user requests and send responses

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🎯 Learning Objectives

By completing all parts, you will understand:

• ✅ Virtual Environments (venv) - Creating isolated project environments
• ✅ App Routing - Using @app.route() to map URLs to functions
• ✅ Jinja2 Templates - Passing Python variables to HTML
• ✅ The Request-Response Cycle - How browsers and servers communicate
• ✅ Dynamic Routing - Creating flexible URL patterns

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🛠️ Initial Setup (Do This First!)

Step 1: Open Terminal in VS Code

Navigate to this project folder.

Step 2: Create Virtual Environment

python -m venv venv

Step 3: Activate Virtual Environment

Windows (Command Prompt):

venv\Scripts\activate

Windows (PowerShell):

venv\Scripts\Activate.ps1

Mac/Linux:

source venv/bin/activate

You should see (venv) at the beginning of your terminal line.

Step 4: Install Flask

pip install flask

Step 5: Create .gitignore File

Create a .gitignore file in the root folder with the following content:

venv/
__pycache__/
*.pyc
.env

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📂 Repository Structure

study-flask/
├── README.md           # You are here!
├── part-1/             # Hello Flask - The Basics
├── part-2/             # Templates - Rendering HTML
├── part-3/             # Jinja2 - Passing Variables
├── part-4/             # Dynamic Routes - Multiple Pages
└── part-5/             # Mini Project - Personal Website

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📚 Parts Overview

Part	Topic	What You'll Learn
Part 1	Hello Flask	Minimal Flask app, @app.route, running the server
Part 2	Templates	templates/ folder, render_template() function
Part 3	Jinja2 Variables	Passing data from Python to HTML with {{ }}
Part 4	Dynamic Routes	Multiple routes, URL parameters with <variable>
Part 5	Mini Project	Build a complete personal website with Flask

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🚀 How to Run Each Part

1. Make sure your virtual environment is activated (you see (venv))
2. Navigate to the part folder:

   cd part-1

3. Run the Flask app:

   python app.py

4. Open your browser and go to: http://localhost:5000
5. Press Ctrl+C in terminal to stop the server

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📤 Submission Checklist

After completing all parts, submit:

1. Screenshot 1: Terminal showing (venv) activated and Flask server running
2. Screenshot 2: Browser at localhost:5000 showing your website
3. Screenshot 3: Your app.py code highlighting the @app.route

Caption: "Successfully launched my first Python server! My personal website is now being served by Flask."

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💡 Tips for Success

• Always activate venv before running any Flask app
• If you see an error, read it carefully - Python errors are helpful!
• Use debug=True during development to see live changes
• Press Ctrl+C to stop the server before running a different part

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🔗 Quick Reference

# Minimal Flask App Structure
from flask import Flask          # Import Flask
app = Flask(__name__)            # Create app instance

@app.route('/')                  # Define route (URL path)
def home():                      # Function that handles the route
    return "Hello Flask!"        # Response sent to browser

if __name__ == '__main__':
    app.run(debug=True)          # Start the server

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Happy Learning! 🎉