Giorgos Giagas wrote: > Hi all, > I have started using ctypes and I am having some questions I can't > seem to find the answers to. > > There is a structure referenced by a pointer in an other structure and > I want to see if it is one of the structures I have pointers to. > So what I think I need is a way to compare 2 pointer's memory > location. I can't find a way to do this. Pointer comparisons don't > work. Is there something else I should do?
Use addressof on the contents of your pointers. > The other thing is more of a curiosity... The documentation says that > I need to keep references to structures so they don't get freed is > this also true for structures returned as pointers? What about > structures that I cast to something else? I guess the largest of the > two casts gets freed like it should... can someone confirm this? The one has nothing to do with the other. If you create a struct and pass e.g. a pointer to it into a DLL, you need to keep a reference, otherwise the struct will be deallocated and the pointer is dangling. If you have a pointer and cast it to some structure, you get a structure object (in python) that points to a certain memory portion. But GCing that object doesn't do anything to the memory location. Diez -- http://mail.python.org/mailman/listinfo/python-list
