# `rlcompleter` — Completion function for GNU readline

Source code: Lib/rlcompleter.py

The `rlcompleter` module defines a completion function suitable to be passed to `set_completer()` in the `readline` module.

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. The method provides completion of valid Python identifiers and keywords.

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. Unless Python is run with the `-S` option, the module is automatically imported and configured (see Readline configuration).

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

class rlcompleter.Completer

  Completer objects have the following method:

  complete(text, state)

    Return the next possible completion for text.

    When called by the `readline` module, this method is called successively with `state == 0, 1, 2, ...` until the method returns `None`.

    If called for text that doesn’t include a period character (`'.'`), it will complete from names currently defined in `__main__`, `builtins` and keywords (as defined by the `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 `__getattr__()`) up to the last part, and find matches for the rest via the `dir()` function. Any exception raised during the evaluation of the expression is caught, silenced and `None` is returned.