On Wed, Dec 30, 2009 at 01:10:05AM -0800, Robert Bradshaw wrote:
> > Does anyone know a trick to access the global variables for the "main"
> > scope?
> >
> > In the attached patch (for 4.2; untested on 4.3), I am implementing
> > the following in sage.misc.misc_c:
> >
> > def inject_variable(name, value):
> > """
> > sage: from sage.misc.misc_c import inject_variable
> > sage: inject_variable("a", 314)
> > sage: a
> > 314
> > """
> > G = globals()
> > G[name] = value
> >
> > When called from the interpreter, this works just fine. However, the
> > purpose is to call this function from library code, and then it
> > breaks.
> >
> > More precisely, if I call this from a Python function, say
> > `sage.misc.misc.inject_variable_test` as in the patch, then the
> > globals() call returns instead the global variables for the module
> > `sage.misc.misc`.
> >
> > Tips most welcome!
>
> This is because inject_variable is a hack based on the fact that Pyrex/
> Cython has a broken implementation of globals()--it should refer to
> the module its in, but instead it ends up getting to the last
> registered globals in the thread call stack. (I have intentionally not
> "fixed" this as I did for locals() because we rely on the broken
> behavior, and there are issues for setting a cdef "global").
>
> What we should do is walk up the stack, perhaps looking for __name__
> == '__main__'
Which is now implemented in #7776. Robert: do you mind reviewing it?
Then, it will be possible to fix inject_variables to use it, freeing
the road for a proper cython global :-)
Thanks Robert for the tip!
Cheers,
Nicolas
--
Nicolas M. Thiéry "Isil" <nthi...@users.sf.net>
http://Nicolas.Thiery.name/
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