Python Simple Web App

1. What is a Simple Web App?

A web app is a program that:
👉 Runs on a server
👉 Opens in a web browser
👉 Shows pages like a website

In simple words:
👉 Python runs in the backend
👉 Browser shows the output

2. What Will We Build?

We will build a very simple Python web app that:
✔ Shows a home page
✔ Shows another page
✔ Uses Python code to respond

We will use Flask, which is easy and beginner-friendly.

3. What is Flask?

Flask is a Python web framework.

In simple words:
👉 Flask helps Python talk to the browser
👉 Flask makes web apps easy
👉 Flask is perfect for beginners

4. Install Flask (One Time)

Run this command in terminal:

5. Create Your First Simple Web App

Create a file named:

6. Full Simple Web App Code

✅ Complete Working Code

7. How to Run This Web App

1️⃣ Save the file
2️⃣ Open terminal in that folder
3️⃣ Run:

4️⃣ Open browser and go to:

8. Output in Browser

Home Page (/)

About Page (/about)

9. How This Code Works (Easy Explanation)

🔹 Import Flask

👉 Brings Flask into Python.

🔹 Create App

👉 Creates the web app.

🔹 Route (@app.route)

👉 Tells Flask:
“When user opens this URL, run this function.”

🔹 Function Returns Text

👉 This text is shown in browser.

🔹 Run App

👉 Starts the server.

10. Add Dynamic Content (User Name)

Example

Open in browser:

Output:

11. Simple HTML in Web App

Example

12. Real-World Use of Simple Web App

This type of app is used for:
✔ Learning backend
✔ Small tools
✔ APIs
✔ Dashboards
✔ Prototypes

13. Common Beginner Mistakes

❌ Forgetting to install Flask
❌ Running wrong file
❌ Not saving file
❌ Port already running

14. How to Improve This Web App

✔ Add HTML templates
✔ Add form input
✔ Add database
✔ Convert to full website
✔ Deploy online

15. What You Learn from This Project

✔ Web basics
✔ Flask framework
✔ URL routing
✔ Backend logic
✔ Real-world Python use

16. Summary (Python Simple Web App)

✔ First real web project
✔ Beginner friendly
✔ Uses Flask
✔ Runs in browser
✔ Strong foundation for web development

📘 PERFECT MINI / FINAL PROJECT FOR PYTHON eBOOK

This project is ideal for:

• Python beginners

• Web development starters

• Students

• Practice & demos

• Resume projects

If you want next, I can write:

• Web App with HTML Templates

• Web App with Form & Input

• Web App with Database

• Flask Final Project

Just tell me 😊