I'm running both emacs 23 and 24 with "--no-init-file" to avoid loading my customizations. But then I explicitly load my ancient version of python-mode.el (version 3.105, last copyright notice 1998), and see the same behavior I'm about to describe, so I believe it's core emacs, not python.
Consider this code (the * marks the cursor location):
*def emacs_is_fun():
for x in range(3):
print(x)
Put the cursor at column 4 at the start of "def".
With emacs 23, running mark-sexp selects "def".
With emacs 24, mark-sexp selects the entire code block, to the end
of the print statement.
This isn't bad. The main problem is this common usage:
*very_long_var_name[very_long_expn] += long_function_call(long_arg_list, blah)
Again, the cursor is at the start of the printable part of the line, col 4.
In emacs 23, mark-sexp selects very_long_var_name.
In emacs 24, mark-sexp selects the full line, from col 4 to the end.
I've been using Ctrl-alt-space alt-w to quickly save variable names.
(Or alt-2 ctrl-alt-space alt-w to save a ref expression.) Now it's
gone. It's emacs, so this must be customizable, but I haven't found
where the new behaviour is implemented (and remember I'm using a python-mode
that is about 15 years old). What do I need to put in my .emacs file?
@Eric Interesting. Thanks for the context in the comment of my other answer.
I think you may just want this then:
(add-hook 'python-mode-hook (lambda () (setq forward-sexp-function nil)))
From comments inside python-mode built-in emacs 24 (which I think you may be getting instead)
At last but not least the specialized
python-nav-forward-sexpallows easy navigation between code blocks. If you prefercc-mode-likeforward-sexpmovement, settingforward-sexp-functionto nil is enough...
This gels closer to what I think of a sexp as, like mentioned in my other answer, but outside of lisp a sexp seems at least somewhat ambiguous.