Thanks for the patch! The amount of unrelated changes (mostly removing ">>>" empty prompts) makes this a bit hard to review.

Also, I don't think it is too important to link to the "ctypes" module from within the docs of ctypes :)

Please separate out the implementation of the Union classes into a separate patch.

The Array docs look good to me.  The _Pointer docs talk about "reading and writing the elements using standard subscript and slice accesses".  That is true for pointers pointing to arrays, but ".contents" should be mentioned as well.