Python in a Nutshell, 2nd Edition

Richer-Text I/O

The tools we have covered so far support the minimal subset of text I/O functionality that all platforms supply. Most platforms also offer richer-text I/O capabilities, such as responding to single keypresses (not just entire lines of text) and showing text in any spot on the terminal (not just sequentially).

Python extensions and core Python modules let you access platform-specific functionality. Unfortunately, various platforms expose this functionality in different ways. To develop cross-platform Python programs with rich-text I/O functionality, you may need to wrap different modules uniformly, importing platform-specific modules conditionally (usually with the try/except idiom covered in try/except in try/except).

The readline Module

The readline module wraps the GNU Readline Library. GNU Readline lets the user edit text lines during interactive input, and recall previous lines for editing and reentry. Readline is installed on many Unix-like platforms, and it’s available at http://cnswww.cns.cwru.edu/~chet/readline/rltop.html. A Windows port (http://starship.python.net/crew/kernr/) is available, but is not widely deployed. Chris Gonnerman’s module, Alternative Readline for Windows, implements a subset of Python’s standard readline module (using a small dedicated .pyd file instead of Readline) and is found at http://newcenturycomputers.net/projects/readline.html. One way to use Readline on Windows is to install Gary Bishop’s version of readline (http://sourceforge.net/projects/uncpythontools ...