c extension finding the module in object initialization

[Robin Becker]

I have a c extension which is intended to implement a module the looks structurally like this


############
a = 1
b = 2

class T:
     def __init__(self):
         self.a = a
         self.b = b
############

so when an object of type T is instantiated it can set up defaults based on the current module values of a and b.

In the past using old style single phase module creation the init function for the type could look up the module by 
using the PyState_FindModule function. In the new world where we can implement c extensions which might work with 
multiple interpreters (multi-phase creation). The docs say PyState_FindModule won't work for those and indeed it returns 
NULL so is useless.

Is there a way I can set the current module onto the type definition during the module's exec function? I thought it 
would be easy to add at the point in the exec where I'm doing this to the module, m,

TType.tp_base = &PyBaseObject_Type;
if(PyType_Ready(&TType)<0) goto fail;
if(PyModule_AddObject(m,"T", (PyObject *)&TType)<0) goto fail;

but I don't see the place in the type where I can add these sorts of dynamic attributes. The basic_size is for the 
created objects.

The created type does have a __dict__ which is a mappingproxy. I wondered when that actually gets instantiated.

I can see that the type has a __module__ attribute after the module is imported and I suppose if I can find the 
'current' interpreter I might use the __module__ to locate the module object via PyImport_GetModuleDict.

Any expertise or advice gratefully received.
--
Robin Becker