[Python-Dev] __future__ and the interactive interpreter prompt

[Guido van Rossum]

> from __future__ import nested_scopes is accepted at the interactive
> interpreter prompt but has no effect beyond the line on which it was
> entered.  You could use it with lambdas entered following a
> semicolon, I guess.
> 
> I would rather see the future statement take effect for the remained
> of the interactive interpreter session.  I have included a first-cut
> patch below that makes this possible, using an object called
> PySessionState.  (I don't like the name, but don't have a better one;
> PyCompilerFlags?)
> 
> The idea of the session state is to record information about the state
> of an interactive session that may affect compilation.  The
> state object is created in PyRun_InteractiveLoop() and passed all the
> way through to PyNode_Compile().
> 
> Does this seem a reasonable approach?  Should I include it in the
> beta?  Any name suggestions.

I'm not keen on changing the prototypes for PyNode_Compile() and
PyRun_InteractiveOne().  I suspect that folks doing funky stuff might
be calling these directly.

Would it be a great pain to add ...Ex() versions that take a session
state, and have the old versions call this with a made-up dummy
session state?

--Guido van Rossum (home page: http://www.python.org/~guido/)