utilize int.from_bytes

Lib/uuid.py

@@ -147,7 +147,7 @@ class UUID(object):
             if len(bytes) != 16:
                 raise ValueError('bytes is not a 16-char string')
             assert isinstance(bytes, bytes_), repr(bytes)
-            int = int_(('%02x'*16) % tuple(bytes), 16)
+            int = int_.from_bytes(bytes, byteorder='big')
         if fields is not None:
             if len(fields) != 6:
                 raise ValueError('fields is not a 6-tuple')