Editing a function in-memory and in-place

[Ian Bicking]

I got a puzzler for y'all.  I want to allow the editing of functions
in-place.  I won't go into the reason (it's for HTConsole --
http://blog.ianbicking.org/introducing-htconsole.html), except that I
really want to edit it all in-process and in-memory.  So I want the
identity of the function to remain the same, even as I edit the body
and hopefully the signature too.

Well, the reason is that I want to edit any function object, without
having to know who has a reference to the function.  This way editing a
function or a method or a property.fget can all be done in the same
way.

The func_code attributes of functions is writable, but I don't know how
to create the proper code object.  Just compiling a new body isn't good
enough.