🧮 Python Web Servers: CGI, WSGI & Socket

Overview

This project explores three different ways to serve web content using pure Python—no frameworks. Each server demonstrates a different backend architecture style:

1. CGI Calculator – Traditional Common Gateway Interface server
2. WSGI Book Catalog – Web Server Gateway Interface using TinyDB
3. Socket HTTP Server – Raw socket implementation of an HTTP server

Ideal for learning fundamental web backend mechanics and Python networking.

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📁 Project Structure

.
├── cgi/                # CGI calculator
│   └── cgi-bin/
│       └── cgi_calc.py
├── wsgi/               # Book catalog using WSGI + TinyDB
│   ├── main.py
│   ├── initial_books.json
│   └── books_db.json
├── simple_server/      # HTTP server using sockets
│   ├── http_server.py
│   ├── tests.py
│   ├── unit-tests.py
│   └── webroot/
│       ├── a_web_page.html
│       └── images/
└── README.md

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🔢 Part 1: CGI Calculator

A web-based calculator implemented with CGI. Accepts operands and operations via query string:

Example usage:

http://127.0.0.1:8000/cgi-bin/cgi_calc.py?user=jdoe&operand=11&operand=7&operation=div

Run:

cd cgi
python -m http.server --cgi

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📚 Part 2: WSGI Book Catalog

A WSGI server using TinyDB to manage a searchable book catalog. Users can:

• View all books
• Add new books
• Search by title, author, and year

Example search queries:

http://localhost:8000/books/search?title=1984
http://localhost:8000/books/search?year=1925&title=The%20Great%20Gatsby

Run:

cd wsgi
python -m venv .venv && source .venv/bin/activate
pip install tinydb
python main.py

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🌐 Part 3: Raw Socket HTTP Server

Implements an HTTP 1.1 server using Python sockets. Supports:

• Directory browsing
• MIME-type detection
• Static file serving (HTML, text, images, etc.)

Run:

cd simple_server
python -u http_server.py

Then visit:

• http://localhost:10000/a_web_page.html
• http://localhost:10000/images/sample_1.png

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✅ Tests

The socket server includes basic tests using unittest:

python unit-tests.py
python tests.py

📌 Note: You may need to add a delay in the test setup to ensure the server boots before tests run.

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🧪 Learning Objectives

• Understand core differences between CGI, WSGI, and socket-level web servers.
• Learn request parsing, routing, and response generation at different abstraction levels.
• Gain experience with Python’s standard library: http.server, wsgiref, socket, and TinyDB.

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🪪 License

This project is licensed under the MIT License.

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🧠 Author

Uriah McKinney
Senior Technical Program Manager, Backend Developer-in-Training
GitHub • LinkedIn

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🗃️ To-Do / Future Work

• Add logging for request tracing
• Dockerize the WSGI app
• Optional: Execute .py scripts dynamically in the socket server