How does CO_FUTURE_DIVISION compiler flag get propagated?

[Terry]

I've built a Python app for the iPhone, http://www.sabonrai.com/PythonMath/.

Like embedding Python in another app, it uses PyRun_SimpleString() to
execute commands entered by the user. For evaluating expressions, it
uses PyEval_EvalCode() with the dictionary from the __main__ module.

Future division ("from __future__ import division") works within
scripts executed by import or execfile(). However, it does not work
when entered interactively in the interpreter like this:

You get classic (integer) division, but if you enter it as follows,
you get future (float) division.

It appears that the CO_FUTURE_DIVISION compiler flag is not being
retained in the interpreter so that later commands get compiled
without that flag.

I found a hint in
http://groups.google.com/group/comp...lnk=gst&q=co_future_division#960e47f572a59711,
but I don't see that PyRun_SimpleStringFlags returns the flags it
uses. I guess I could watch for the user to enter the import command
but that's really brittle.

Thanks.

 

[Hrvoje Niksic]

Future division ("from __future__ import division") works within
scripts executed by import or execfile(). However, it does not work
when entered interactively in the interpreter like this:

Are you referring to the interactive interpreter normally invoked by
just running "python"? That seems to work for me:

Python 2.7.1+ (r271:86832, Apr 11 2011, 18:13:53)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.0.6666666666666666

 

[Terry]

Future division ("from __future__ import division") works within
scripts executed by import or execfile(). However, it does not work
when entered interactively in the interpreter like this:

Are you referring to the interactive interpreter normally invoked by
just running "python"?  That seems to work for me:

Python 2.7.1+ (r271:86832, Apr 11 2011, 18:13:53)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.>>>2/3
0
0.6666666666666666

Yes, that works for me on my Mac. The problem I'm having is in a
Python interpreter that I built for the iPhone. It uses
PyRun_SimpleString() to execute user entered commands. After you
import future division, it does not seem to remember it on subsequent
commands.