[Cython] dict set value

[Greg Ewing]

Robert Bradshaw wrote:

>> it still generates inefficient code via PyObject, not via PyDict_SetItem:
>>
>> PyObject_SetItem(((PyObject *)__pyx_v_1a_a), __pyx_kp_1, __pyx_int_1)

Keep in mind that the difference in efficiency is very small,
since there is a direct path from PyObject_SetItem via the
object's mp_setitem slot to the relevant C function. There
isn't even any type test involved.

The type-dependent optimisations which are implemented are
more significant, since they avoid type tests, method
lookups and/or conversion between C and Python data.

-- 
Greg