I noticed that Houdini comes loaded with *most* of Python, but it is strangely missing the library (*.lib) files. In Python proper they are found in the “libs” folder. Some of python's built-in modules (even the ones that come with Houdini) use them (for example, ctypes __init__.py). I tried to add them myself by creating a “libs” folder in Houdini's python folder but they weren't recognized. I also tried adding them under Houdini x.x.x/scripts/python but no luck there either.

I'm correct in that they are not included right? Does anyone know how to add them to Houdini?

I think I figured out my problem. It wasn't the _ctypes.lib that's being called but the _ctypes.pyd. Houdini doesn't have it and neither does the 64-bit Python 2.5. So either I'll need to work on compiling my own 64-bit pyd for ctypes or go to 32 bit Houdini and copy the _ctypes.pyd from the 32-bit Python install and throw it in the ctypes folder (which worked). I thought I could take the 64-bit Python 2.6 _ctypes.pyd and use it but it's throwing an error because it's compiled with VC9.