Allow for the database to produce a UUID instance

Some database adapters (specifically, pg8000) already produce a uuid.UUID()
instance for UUID columns. Account for this.

(cherry picked from commit e80a5adfd406e2392cfaad687e8b3f0ae9ed4e11)

diff --git a/doc/build/core/custom_types.rst b/doc/build/core/custom_types.rst
index 64f91b23fcc036bee762bcbb4f5b687c401ee282..e85601f1728b07b56da7b1a53450684d5dca6032 100644 (file)
--- a/doc/build/core/custom_types.rst
+++ b/doc/build/core/custom_types.rst
@@ -163,7 +163,9 @@ binary in CHAR(16) if desired::
             if value is None:
                 return value
             else:
-                return uuid.UUID(value)
+                if not isinstance(value, uuid.UUID):
+                    value = uuid.UUID(value)
+                return value
 
 Marshal JSON Strings
 ^^^^^^^^^^^^^^^^^^^^