On 20/11/2010 16:06, Michael Foord wrote:
On 20/11/2010 16:01, Nick Coghlan wrote:
[snip...]
The retrieval of __class__ is a
normal lookup on the object, so it can trigger all of the things
getattr_static is trying to avoid (unavoidable if you want to support
proxy classes at all), and the lookup of __mro__ invokes all of those
things on the metaclass.
__class__ and mro lookup are noted in the docs as being exceptions. We
could actually remove the __class__ lookup from the list of exceptions
by using type(...) instead of obj.__class__.
Done.
I'll see if I'm still of the same opinion after I sleep on it, but my
first impression of the docs was that they slightly oversold the
strength of the "doesn't execute arbitrary code" aspect of the new
function. The existing caveats were all relating to when getattr() and
getattr_static() might give different answers, while the additional
caveats I was suggesting related to cases where arbitrary code may
still be executed.
I'm happy to change the wording to make the promise less strong.
I've also removed the __mro__ exception. This is done with:
type.__dict__['__mro__'].__get__(klass)
If you can think of any other exceptions then please let me know.
Michael
All the best,
Michael
Cheers,
Nick.
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