Antoine: "I think https://github.com/python/cpython/pull/3796 is a better resolution.  It creates an optional _uuid C extension to avoid ctypes if possible *and* also loads system functions lazily."

Implementing bpo-20519 is a very good idea. But I still like the idea of putting all these ugly functions to get the node and geneate a UUID1 object in a different module, since most of these code is not used on most platforms.

Antoine: Would you mind to modify your PR 3796 to only implement bpo-20519? I would prefer to reorganize uuid.py in a second step. It will be easy to review and easy to discuss what is the best option.