sockets — raw TCP / UDP

Almost every networked Python library is built on socket. You rarely use it directly — but knowing it demystifies HTTP, DNS, and async I/O.

import socket
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
    s.connect(("example.com", 80))
    s.sendall(b"GET / HTTP/1.0\r\nHost: example.com\r\n\r\n")
    data = s.recv(4096)
    print(data[:80])

**Higher-level alternatives**

• HTTP → httpx / requests
• Async TCP → asyncio.open_connection
• Many clients → selectors (level-triggered I/O multiplexing)

> 🧪 Concept-only here — the browser sandbox has no raw socket access.