[1.7.x] Added django.utils.six.buffer_types

and used it in the Oracle SchemaEditor. Refs #22715.

Backport of 06c0e740a4 from master

django/db/backends/oracle/schema.py

@@ -24,8 +24,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
             return "'%s'" % value
         elif isinstance(value, six.string_types):
             return "'%s'" % six.text_type(value).replace("\'", "\'\'")
-        elif (isinstance(value, six.memoryview) or
-              six.PY3 and isinstance(value, bytes)):
+        elif isinstance(value, six.buffer_types):
             return "'%s'" % force_text(binascii.hexlify(value))
         elif isinstance(value, bool):
             return "1" if value else "0"

django/utils/six.py

@@ -666,6 +666,7 @@ if PY3:
     _assertRaisesRegex = "assertRaisesRegex"
     _assertRegex = "assertRegex"
     memoryview = memoryview
+    buffer_types = (bytes, bytearray, memoryview)
 else:
     _assertRaisesRegex = "assertRaisesRegexp"
     _assertRegex = "assertRegexpMatches"
@@ -676,6 +677,7 @@ else:
         memoryview = memoryview
     else:
         memoryview = buffer
+    buffer_types = (bytearray, memoryview)
 
 
 def assertRaisesRegex(self, *args, **kwargs):