Python readline 模块，__file__() 实例源码

def setup_readline():
    """Sets up the readline module and completion supression, if available."""
    global RL_COMPLETION_SUPPRESS_APPEND, RL_LIB, RL_CAN_RESIZE
    if RL_COMPLETION_SUPPRESS_APPEND is not None:
        return
    try:
        import readline
    except ImportError:
        return
    import ctypes
    import ctypes.util
    readline.set_completer_delims(' \t\n')
    if not readline.__file__.endswith('.py'):
        RL_LIB = lib = ctypes.cdll.LoadLibrary(readline.__file__)
        try:
            RL_COMPLETION_SUPPRESS_APPEND = ctypes.c_int.in_dll(
                lib, 'rl_completion_suppress_append')
        except ValueError:
            # not all versions of readline have this symbol, ie Macs sometimes
            RL_COMPLETION_SUPPRESS_APPEND = None
        RL_CAN_RESIZE = hasattr(lib, 'rl_reset_screen_size')
    env = builtins.__xonsh_env__
    # reads in history
    readline.set_history_length(-1)
    ReadlineHistoryAdder()
    # sets up IPython-like history matching with up and down
    readline.parse_and_bind('"\e[B": history-search-forward')
    readline.parse_and_bind('"\e[A": history-search-backward')
    # Setup Shift-Tab to indent
    readline.parse_and_bind('"\e[Z": "{0}"'.format(env.get('INDENT')))

    # handle tab completion differences found in libedit readline compatibility
    # as discussed at http://stackoverflow.com/a/7116997
    if readline.__doc__ and 'libedit' in readline.__doc__:
        readline.parse_and_bind("bind ^I rl_complete")
    else:
        readline.parse_and_bind("tab: complete")