Update doc string

Author: aisk

Lib/uuid.py

@@ -211,7 +211,7 @@ class UUID:
 
         is_safe     An enum indicating whether the UUID has been generated in
                     a way that is safe for multiprocessing applications, via
-                    uuid_generate_time_safe(3).
+                    uuid_generate_time_safe(3) or UuidCreateSequential().
     """
 
     __slots__ = ('int', 'is_safe', '__weakref__')
@@ -245,7 +245,8 @@ def __init__(self, hex=None, bytes=None, bytes_le=None, fields=None,
 
         is_safe is an enum exposed as an attribute on the instance.  It
         indicates whether the UUID has been generated in a way that is safe
-        for multiprocessing applications, via uuid_generate_time_safe(3).
+        for multiprocessing applications, via uuid_generate_time_safe(3) or
+        UuidCreateSequential().
         """
 
         if [hex, bytes, bytes_le, fields, int].count(None) != 4:
@@ -757,7 +758,9 @@ def uuid1(node=None, clock_seq=None):
     """Generate a UUID from a host ID, sequence number, and the current time.
     If 'node' is not given, getnode() is used to obtain the hardware
     address.  If 'clock_seq' is given, it is used as the sequence number;
-    otherwise a random 14-bit sequence number is chosen."""
+    otherwise a random 14-bit sequence number is chosen.  If neither is
+    given and the platform provides a version-1 UUID generator, it is used
+    instead."""
 
     # When the system provides a version-1 UUID generator, use it.
     if node is clock_seq is None: