If wr_object is weakly referenced, wr_object has a doubly-linked NULL- terminated list of weak references to it. These are the list pointers. If wr_object goes away, wr_object is set to Py_None, and these pointers have no meaning then.
See Implementation
If wr_object is weakly referenced, wr_object has a doubly-linked NULL- terminated list of weak references to it. These are the list pointers. If wr_object goes away, wr_object is set to Py_None, and these pointers have no meaning then.