Word completion for GNU readline.
The completer completes keywords, built-ins and globals in a selectable
namespace (which defaults to __main__); when completing NAME.NAME..., it
evaluates (!) the expression up to the last dot and completes its attributes.
It's very cool to do "import sys" type "sys.", hit the completion key (twice),
and see the list of names defined by the sys module!
Tip: to use the tab key as the completion key, call
- Exceptions raised by the completer function are *ignored* (and generally cause
the completion to fail). This is a feature -- since readline sets the tty
device in raw (or cbreak) mode, printing a traceback wouldn't work well
without some complicated hoopla to save, reset and restore the tty state.
- The evaluation of the NAME.NAME... form may cause arbitrary application
defined code to be executed if an object with a __getattr__ hook is found.
Since it is the responsibility of the application (or the user) to enable this
feature, I consider this an acceptable risk. More complicated expressions
(e.g. function calls or indexing operations) are *not* evaluated.
- GNU readline is also used by the built-in functions input() and
raw_input(), and thus these also benefit/suffer from the completer
features. Clearly an interactive application can benefit by
specifying its own completer function and using raw_input() for all
- When the original stdin is not a tty device, GNU readline is never
used, and this module (and the readline module) are silently inactive.
|__all__ = ['Completer']|