Learning Python with Raspberry Pi

Chapter 7

Networked Python

THE WORLD TODAY is more connected than it's ever been, and almost everything that you do on computers has some form of online component. The Raspberry Pi is no different. As long as you have a Model B, or a wireless USB dongle, getting your Pi connected to the Internet is trivial. There's the Midori browser you can use to surf the web, and mail clients are available. These are good for consuming content—getting information off the web and using services that other people have created. The power of the Raspberry Pi, however, lies in creating things. With a few lines of Python, you can grab information off the web or use your Raspberry Pi to serve up content and services to the world. Read on to find out how.

Understanding Hosts, Ports, and Sockets

To communicate with another computer, you need to know where to send data to. It might be that you're just sending information to another computer in the same room, or you might be sending it halfway round the world. Regardless, you need to specify an address. The standard way of locating computers is by Internet Protocol (IP) address. There are two types of IP address, version 4 and version 6. At the time of writing, version 4 (IPv4) is almost universally used, so you'll read only about it. IPv6 addresses work in the same basic way, so you shouldn't have any difficulty using these should they become mainstream any time soon.

Locating Computers with IP Addresses

IPv4 addresses contain four numbers separated ...