some python ctypes stuff in Rtree
I've been working with and on the Rtree python module. It's some cool work done by Howard Butler (hobu) (originally with Sean Gillies ) to make python bindings for the Spatial Index C++ library by Marios Hadjieleftheriou which provides various tree structures for efficient spatial searches in n-dimensions. Hobu has written a C API for that along with a new ctypes wrapper to that API which appears in Rtree 0.5 and greater. There is some cool ctypes stuff in there which I'm starting to understand. From the website: ctypes is a foreign function library for Python. It provides C compatible data types, and allows calling functions in DLLs or shared libraries. It can be used to wrap these libraries in pure Python. as a simple example of how ctypes works we can pretend there's no atan() in python's math module and access the one from libm in c like this: import ctypes libm = ctypes.CDLL('libm.so.6') # the following 2 lines correspond to the c signature: double...