Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote:
> I'm working with the readline module, and I'm trying to set a key
> combination to process the current command line by calling a known
> function, *and* enter the command line.

> Something along the lines of:

> * execute function spam() in some context where it can access
>   the current command line as a string
> * enter the command line

> Function spam() may or may not modify the command line.

> Here is what I have got so far: I can discard the current line and call a
> function:

> readline.parse_and_bind(r'"\C-p": "%cspam()\n"' % 0x15)  # ^U

> binds ctrl-P to the key combinations `ctrl-U spam() Enter`, which clears
> the command line before entering spam().

> If I leave out the ctrl-U, I'll get a SyntaxError or other exception,
> e.g. command line `x = 123` gets transformed into `x = 123spam()`.

> This is not suitable:

> readline.parse_and_bind(r'"\C-p": "; spam()\n"')

> because it changes the command line. It's okay for spam() itself to
> modify the command line, but the key binding should not.

> I tried to do this:

> readline.parse_and_bind(r'"\C-p": "\nspam()\n"')

> but it gives me a segmentation fault, which is a little less helpful than
> I had expected.

> This Stackoverflow question suggests that what I want is not possible in
> vanilla Python:

> http://stackoverflow.com/questions/11680356

> but I'm a stubborn guy and I have not given up yet. Any suggestions?

> (P.S. I'm aware of IPython, I want to get this working in the standard
> CPython interpreter.)

> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list