gh-130843: expose 48-bit timestamp for UUIDv7 (#131838)

Doc/library/uuid.rst

@@ -103,28 +103,29 @@ which relays any information about the UUID's safety, using this enumeration:
      - Meaning
 
    * - .. attribute:: UUID.time_low
-     - The first 32 bits of the UUID.
+     - The first 32 bits of the UUID. Only relevant to version 1.
 
    * - .. attribute:: UUID.time_mid
-     - The next 16 bits of the UUID.
+     - The next 16 bits of the UUID. Only relevant to version 1.
 
    * - .. attribute:: UUID.time_hi_version
-     - The next 16 bits of the UUID.
+     - The next 16 bits of the UUID. Only relevant to version 1.
 
    * - .. attribute:: UUID.clock_seq_hi_variant
-     - The next 8 bits of the UUID.
+     - The next 8 bits of the UUID. Only relevant to versions 1 and 6.
 
    * - .. attribute:: UUID.clock_seq_low
-     - The next 8 bits of the UUID.
+     - The next 8 bits of the UUID. Only relevant to versions 1 and 6.
 
    * - .. attribute:: UUID.node
-     - The last 48 bits of the UUID.
+     - The last 48 bits of the UUID. Only relevant to version 1.
 
    * - .. attribute:: UUID.time
-     - The 60-bit timestamp.
+     - The 60-bit timestamp for version 1 and 6,
+       or the 48-bit timestamp for version 7.
 
    * - .. attribute:: UUID.clock_seq
-     - The 14-bit sequence number.
+     - The 14-bit sequence number. Only relevant to versions 1 and 6.
 
 
 .. attribute:: UUID.hex

Lib/test/test_uuid.py

@@ -913,6 +913,7 @@ class BaseTestUUID:
                 equal(self.uuid._last_counter_v7, counter)
 
                 unix_ts_ms = timestamp_ms & 0xffff_ffff_ffff
+                equal(u.time, unix_ts_ms)
                 equal((u.int >> 80) & 0xffff_ffff_ffff, unix_ts_ms)
 
                 equal((u.int >> 75) & 1, 0)  # check that the MSB is 0
@@ -966,6 +967,7 @@ class BaseTestUUID:
                 urand.assert_called_once_with(10)
                 equal(self.uuid._last_timestamp_v7, timestamp_ms)
                 equal(self.uuid._last_counter_v7, counter)
+                equal(u1.time, timestamp_ms)
                 equal((u1.int >> 64) & 0xfff, counter_hi)
                 equal((u1.int >> 32) & 0x3fff_ffff, counter_lo)
                 equal(u1.int & 0xffff_ffff, tail)
@@ -988,6 +990,7 @@ class BaseTestUUID:
                 equal(self.uuid._last_timestamp_v7, timestamp_ms)
                 # 42-bit counter advanced by 1
                 equal(self.uuid._last_counter_v7, counter + 1)
+                equal(u2.time, timestamp_ms)
                 equal((u2.int >> 64) & 0xfff, counter_hi)
                 equal((u2.int >> 32) & 0x3fff_ffff, counter_lo + 1)
                 equal(u2.int & 0xffff_ffff, next_fail)
@@ -1025,6 +1028,7 @@ class BaseTestUUID:
             equal(u.version, 7)
             equal(self.uuid._last_timestamp_v7, fake_last_timestamp_v7 + 1)
             unix_ts_ms = (fake_last_timestamp_v7 + 1) & 0xffff_ffff_ffff
+            equal(u.time, unix_ts_ms)
             equal((u.int >> 80) & 0xffff_ffff_ffff, unix_ts_ms)
             # 42-bit counter advanced by 1
             equal(self.uuid._last_counter_v7, counter + 1)
@@ -1064,6 +1068,7 @@ class BaseTestUUID:
             # timestamp advanced due to overflow
             equal(self.uuid._last_timestamp_v7, timestamp_ms + 1)
             unix_ts_ms = (timestamp_ms + 1) & 0xffff_ffff_ffff
+            equal(u.time, unix_ts_ms)
             equal((u.int >> 80) & 0xffff_ffff_ffff, unix_ts_ms)
             # counter overflowed, so we picked a new one
             equal(self.uuid._last_counter_v7, new_counter)

Lib/uuid.py

@@ -134,9 +134,16 @@ class UUID:
 
         fields      a tuple of the six integer fields of the UUID,
                     which are also available as six individual attributes
-                    and two derived attributes. The time_* attributes are
+                    and two derived attributes. Those attributes are not
-                    only relevant to version 1, while the others are only
+                    always relevant to all UUID versions:
-                    relevant to versions 1 and 6:
+
+                        The 'time_*' attributes are only relevant to version 1.
+
+                        The 'clock_seq*' and 'node' attributes are only relevant
+                        to versions 1 and 6.
+
+                        The 'time' attribute is only relevant to versions 1, 6
+                        and 7.
 
             time_low                the first 32 bits of the UUID
             time_mid                the next 16 bits of the UUID
@@ -145,7 +152,8 @@ class UUID:
             clock_seq_low           the next 8 bits of the UUID
             node                    the last 48 bits of the UUID
 
-            time                    the 60-bit timestamp
+            time                    the 60-bit timestamp for UUIDv1/v6,
+                                    or the 48-bit timestamp for UUIDv7
             clock_seq               the 14-bit sequence number
 
         hex         the UUID as a 32-character hexadecimal string
@@ -366,6 +374,9 @@ class UUID:
             time_hi = self.int >> 96
             time_lo = (self.int >> 64) & 0x0fff
             return time_hi << 28 | (self.time_mid << 12) | time_lo
+        elif self.version == 7:
+            # unix_ts_ms (48) | ... (80)
+            return self.int >> 80
         else:
             # time_lo (32) | time_mid (16) | ver (4) | time_hi (12) | ... (64)
             #