Python Programming On Win32

PIDDLE: A Python Graphics API

While working on this book, we tried to create a printing system that could handle multiple formats, including Windows and PDF. At the same time, several people in the Python newsgroup felt that it was a real pity everyone was using platform-specific code to draw charts and diagrams, and that it should be possible to come up with a common API that covered several output formats. A team of four— Joe Strout, Magnus Hetland, Perry Stoll, and Andy Robinson—developed a common API during the spring of 1999, and a number of backends and a test suite are available at press time. This has produced some powerful printing solutions, which we explore here.

The API is known as Plug-In Drawing, Does Little Else (PIDDLE) and is available from http://www.strout.net/python/piddle/. The package includes the basic API, test patterns, and as many backends as are deemed stable. The basic API defines classes to represent fonts and colors, and a base class called Canvas , which exposes several drawing methods. The base canvas doesn’t produce any output and exists to define an interface; specific backends implement a canvas to draw on the relevant device or file format.

Let’s quickly run through the main features of the PIDDLE API.