[IPython-user] How to get def, class or other multiline from history to current input?

[Fernando Perez]

Jeff Kowalczyk wrote:
> I'm in the midst of a cold-turkey switch to linux, and one
> of the creature comforts I gave up was PythonWin's treatment
> of multiline python commands as single command history entries.
> 
> When working on a new function I typically iteratively debug in
> the interpreter, for which you really need a keystroke to bring
> back the entire definition into a form which you can edit,
> including entire line additions and removals and resubmit.
> 
> Is there any way to do this?
> 
> Is ipython's line-based editing unsuitable for this, and such
> things only happen in the connected snippet editors (vim, etc.)

ipython's line editing is readline-based, hence it works only for single-line 
editing.  Writing a multi-line terminal editing system requires using curses, 
which is a large, complex and not very portable system.  I simply haven't gone 
that route because it's far too big of a headache.

But there are a few alternatives and tools in ipython to at least help with 
this issue:

- the @edit command allows you to open an editor on the spot, edit something, 
and be back in python.  This is in practice, fairly close to multi-line 
editing.  Note that you can type @edit, define a function (say 'f'), and later 
say '@edit f', and ipython will open again the editor with the temp file where 
f was defined.  Just type 'edit ?' for more details.

- @hist -n will give you a command-line history without line numbers.  You can 
then paste previous input into an editor window if you decide you need to work 
  in a full editing environment with code.

- (X)emacs support:  as of 0.4.0, this is fairly complete, and gives you 
within emacs a very powerful IDE-like environment.  There is a section in the 
manual detailing how to configure it, here's the online link to it:
http://ipython.scipy.org/doc/manual/node3.html#SECTION00034000000000000000

I know none of these are _true_ multiline editing inside ipython itself, but 
in practice I find that it's not such a hindrance.  I hope this helps.

Best,

f