This module implements the version 7 UUIDs, proposed by Peabody and Davis in https://www.ietf.org/id/draft-peabody-dispatch-new-uuid-format-02.html as an extension to RFC4122.

Version 7 has the nice characteristic that the start of a UUID encodes the time with a chronological sort order and potentially ~50ns time resolution, while the end of the UUID includes sufficient random bits to ensure consecutive UUIDs will remain unique.

The 128 bits in the UUID are allocated as follows:

• 36 bits of whole seconds
• 24 bits of fractional seconds, giving approx 50ns resolution
• 14 bits of sequential counter, if called repeatedly in same time tick
• 48 bits of randomness

plus, at locations defined by RFC4122, 4 bits for the uuid version (0b111) and 2 bits for the uuid variant (0b10).

         0                   1                   2                   3
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
t1      |                 unixts (secs since epoch)                     |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
t2/t3   |unixts |  frac secs (12 bits)  |  ver  |  frac secs (12 bits)  |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
t4/rand |var|       seq (14 bits)       |          rand (16 bits)       |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
rand    |                          rand (32 bits)                       |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Indicative timings:

• uuid.uuid4() - 2.4us
• uuid7() - 3.7us
• uuid7(as_type='int') - 1.6us
• uuid7(as_type='str') - 2.5us

> pip install uuid7

>>> from uuid_extensions import uuid7, uuid7str
>>> uuid7()
UUID('061cb26a-54b8-7a52-8000-2124e7041024')

>>> uuid7(0)
UUID('00000000-0000-0000-0000-00000000000')

>>> for fmt in ('bytes', 'hex', 'int', 'str', 'uuid', None):
...     print(fmt, repr(uuid7(as_type=fmt)))
bytes b'\x06\x1c\xb8\xfe\x0f\x0b|9\x80\x00\tjt\x85\xb3\xbb'
hex '061cb8fe0f0b7c3980011863b956b758'
int 8124504378724980906989670469352026642
str '061cb8fe-0f0b-7c39-8003-d44a7ee0bdf6'
uuid UUID('061cb8fe-0f0b-7c39-8004-0489578299f6')
None UUID('061cb8fe-0f0f-7df2-8000-afd57c2bf446')

>>> uuid7str() # Shorthand for uuid7(as_type='str')
'061cb26a-54b8-7a52-8000-2124e7041024'

• Free software: MIT license