[Python-Dev] C-level duck typing

Wed May 16 10:36:03 CEST 2012

 > And, we want this to somehow work with existing Python; we still
 > support users on Python 2.4.
This makes the question out-of-scope for python-dev - we only discuss
new versions of Python here. Old versions cannot be developed anymore
(as they are released already).
> typedef struct {
> unsigned long extension_id;
> void *data;
> } PyTypeObjectExtensionEntry;
>> and then a type object can (somehow!) point to an array of these. The
> array is linearly scanned

It's unclear to me why you think that a linear scan is faster than
a dictionary lookup. The contrary will be the case - the dictionary
lookup (PyObject_GetAttr) will be much faster.
Just make sure to use interned strings, and to cache the interned strings.
Regards,
Martin