I'm also very mistified. It is actually very hard to remove a method form a
cdef'ed class. I tried some stuff to recreate the symptoms but I failed
missarably (I could do it in pure python using del or metaclasses but not
in cython).
What happens if you subclass Parent with a cdef class? Does __getattr__
appear then? And what if you define __getattr__ in this subclass? And what
happens if you subclass sage.structure.category_object.CategoryObject (the
superclass of Parent)?
I looked at sage/structure/parent.pyx and it's size sort of scared me
because it's so huge so maybe it's good to try to persuade the above
questions to find a smaller example.
Le vendredi 27 avril 2012 17:03:22 UTC+2, Simon King a écrit :
>
> Hi John!
>
> On 2012-04-27, John Cremona <john.crem...@gmail.com> wrote:
> > It has __getattribute__ (as you can see by doing
> > sage.structure.parent.Parent.__<tab>
>
> Yes, but that is not defined in sage.structure.parent or
> sage.structure.category_object.
>
> Anyway: Would the existence of __getattribute__ explain why __getattr__ is
> not available as an attribute, even though it is defined and is used?
>
> Apparently not:
>
> sage: cython("""
> ....: cdef class Example(object):
> ....: def __getattr__(self, str name):
> ....: return 1
> ....: """)
> sage: Example.__get<TAB>
> Example.__getattr__ Example.__getattribute__
> sage: Example.__getattr__
> <method '__getattr__' of
> '_home_simon__sage_temp_linux_sqwp_site_2778_tmp_0_spyx_0.Example' objects>
>
> So, there is a __getattribute__, but still one can access __getattr__.
>
> And apparently it is not a Python thing - or at least it isn't a Cython
> thing, since otherwise my example wouldn't work.
>
> Cheers,
> Simon
>
>
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