"""

Unrelated to the patch (same before and after), this looks odd to me:

>>> import uuid
>>> uuid._has_uuid_generate_time_safe is None
True
>>> 
>>> import _uuid
>>> _uuid.has_uuid_generate_time_safe
1
"""

None means "not initialized yet". It's initialized on demand, at the first call of uuid1() or get_node():

$ python3
Python 3.7.0a2+ (heads/master:a5293b4ff2, Nov  6 2017, 12:22:04) 
>>> import uuid
>>> uuid._has_uuid_generate_time_safe  # == None
>>> uuid.uuid1()
UUID('3e5a7628-c2e5-11e7-adc1-3ca9f4650c0c')
>>> uuid._has_uuid_generate_time_safe
1


> [Also, I thought we weren't supposed to use ctypes in the stdlib.]

Antoine's commit a106aec2ed6ba171838ca7e6ba43c4e722bbecd1 avoids ctypes when libuuid is available.

For the other systems without libuuid, well, it was probably simpler to use ctypes. ctypes was more popular a few years ago. The code "just works" and I guess that nobody wants to touch it :-)