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

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

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

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