# 7.21 `rlcompleter` -- Completion function for GNU readline

Availability: Unix.

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

This module is Unix-specific due to its dependence on the `readline` module.

The `rlcompleter` module defines the `Completer` class.

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 `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 PYTHONSTARTUP environment variable) to get automatic `Tab` completion:

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