Enable uuid for pg8000

Enabled UUID support for the pg8000 driver, which supports native Python
uuid round trips for this datatype.  Arrays of UUID are still not supported,
however.

Change-Id: I44ca323c5d9f2cd87327210233bc36a3556eb050
Fixes: #4016

1 files changed, 26 insertions, 2 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/pg8000.py b/lib/sqlalchemy/dialects/postgresql/pg8000.py
index 5f6cd0a3f..3ec7798c3 100644
--- a/lib/sqlalchemy/dialects/postgresql/pg8000.py
+++ b/lib/sqlalchemy/dialects/postgresql/pg8000.py
@@ -70,11 +70,16 @@ from ... import processors
 from ... import types as sqltypes
 from .base import (
     PGDialect, PGCompiler, PGIdentifierPreparer, PGExecutionContext,
-    _DECIMAL_TYPES, _FLOAT_TYPES, _INT_TYPES)
+    _DECIMAL_TYPES, _FLOAT_TYPES, _INT_TYPES, UUID)
 import re
 from sqlalchemy.dialects.postgresql.json import JSON
 from ...sql.elements import quoted_name
 
+try:
+    from uuid import UUID as _python_UUID
+except ImportError:
+    _python_UUID = None
+
 
 class _PGNumeric(sqltypes.Numeric):
     def result_processor(self, dialect, coltype):
@@ -113,6 +118,24 @@ class _PGJSON(JSON):
             return super(_PGJSON, self).result_processor(dialect, coltype)
 
 
+class _PGUUID(UUID):
+    def bind_processor(self, dialect):
+        if not self.as_uuid:
+            def process(value):
+                if value is not None:
+                    value = _python_UUID(value)
+                return value
+            return process
+
+    def result_processor(self, dialect, coltype):
+        if not self.as_uuid:
+            def process(value):
+                if value is not None:
+                    value = str(value)
+                return value
+            return process
+
+
 class PGExecutionContext_pg8000(PGExecutionContext):
     pass
 
@@ -156,7 +179,8 @@ class PGDialect_pg8000(PGDialect):
             sqltypes.Numeric: _PGNumericNoBind,
             sqltypes.Float: _PGNumeric,
             JSON: _PGJSON,
-            sqltypes.JSON: _PGJSON
+            sqltypes.JSON: _PGJSON,
+            UUID: _PGUUID
         }
     )