:mod:`rlcompleter` --- Completion function for GNU readline

.. module:: rlcompleter
   :synopsis: Python identifier completion, suitable for the GNU readline library.

.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>

Source code: :source:`Lib/rlcompleter.py`

The :mod:`rlcompleter` module defines a completion function suitable for the :mod:`readline` module by completing valid Python identifiers and keywords.

When this module is imported on a Unix platform with the :mod:`readline` module available, an instance of the :class:`Completer` class is automatically created and its :meth:`complete` method is set as the :mod:`readline` completer.

Example:

>>> import rlcompleter
>>> import readline
>>> readline.parse_and_bind("tab: complete")
>>> readline. <TAB PRESSED>
readline.__doc__          readline.get_line_buffer(  readline.read_init_file(
readline.__file__         readline.insert_text(      readline.set_completer(
readline.__name__         readline.parse_and_bind(
>>> readline.

The :mod:`rlcompleter` module is designed for use with Python's interactive mode. A user can add the following lines to his or her initialization file (identified by the :envvar:`PYTHONSTARTUP` environment variable) to get automatic :kbd:`Tab` completion:

try:
    import readline
except ImportError:
    print "Module readline not available."
else:
    import rlcompleter
    readline.parse_and_bind("tab: complete")

On platforms without :mod:`readline`, the :class:`Completer` class defined by this module can still be used for custom purposes.

.. method:: Completer.complete(text, state)

   Return the *state*\ th completion for *text*.

   If called for *text* that doesn't include a period character (``'.'``), it will
   complete from names currently defined in :mod:`__main__`, :mod:`__builtin__` and
   keywords (as defined by the :mod:`keyword` module).

   If called for a dotted name, it will try to evaluate anything without obvious
   side-effects (functions will not be evaluated, but it can generate calls to
   :meth:`__getattr__`) up to the last part, and find matches for the rest via the
   :func:`dir` function.  Any exception raised during the evaluation of the
   expression is caught, silenced and :const:`None` is returned.