old_contents: # Copyright 2012 Managed I.T.
  #
  # Author: Kiall Mac Innes <kiall@managedit.ie>
  #
  # Licensed under the Apache License, Version 2.0 (the "License"); you may
  # not use this file except in compliance with the License. You may obtain
  # a copy of the License at
  #
  #      http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  # License for the specific language governing permissions and limitations
  # under the License.
  import uuid
  
  from sqlalchemy.types import TypeDecorator, CHAR
  from sqlalchemy.dialects.postgresql import UUID as pgUUID
  
  
  class UUID(TypeDecorator):
      """Platform-independent UUID type.
  
      Uses Postgresql's UUID type, otherwise uses
      CHAR(32), storing as stringified hex values.
  
      Copied verbatim from SQLAlchemy documentation.
      """
      impl = CHAR
  
      def load_dialect_impl(self, dialect):
          if dialect.name == 'postgresql':
              return dialect.type_descriptor(pgUUID())
          else:
              return dialect.type_descriptor(CHAR(32))
  
      def process_bind_param(self, value, dialect):
          if value is None:
              return value
          elif dialect.name == 'postgresql':
              return str(value)
          else:
              if not isinstance(value, uuid.UUID):
                  return "%.32x" % uuid.UUID(value).int
              else:
                  # hexstring
                  return "%.32x" % value.int
  
      def process_result_value(self, value, dialect):
          if value is None:
              return value
          else:
              return str(uuid.UUID(value))
  
new_contents: # Copyright 2012 Managed I.T.
  #
  # Author: Kiall Mac Innes <kiall@managedit.ie>
  #
  # Licensed under the Apache License, Version 2.0 (the "License"); you may
  # not use this file except in compliance with the License. You may obtain
  # a copy of the License at
  #
  #      http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  # License for the specific language governing permissions and limitations
  # under the License.
  import uuid
  
  from sqlalchemy.types import TypeDecorator, CHAR
  from sqlalchemy.dialects.postgresql import UUID as pgUUID
  
  
  class UUID(TypeDecorator):
      """Platform-independent UUID type.
  
      Uses Postgresql's UUID type, otherwise uses
      CHAR(32), storing as stringified hex values.
  
      Copied verbatim from SQLAlchemy documentation.
      """
      cache_ok = True
      impl = CHAR
  
      def load_dialect_impl(self, dialect):
          if dialect.name == 'postgresql':
              return dialect.type_descriptor(pgUUID())
          else:
              return dialect.type_descriptor(CHAR(32))
  
      def process_bind_param(self, value, dialect):
          if value is None:
              return value
          elif dialect.name == 'postgresql':
              return str(value)
          else:
              if not isinstance(value, uuid.UUID):
                  return "%.32x" % uuid.UUID(value).int
              else:
                  # hexstring
                  return "%.32x" % value.int
  
      def process_result_value(self, value, dialect):
          if value is None:
              return value
          else:
              return str(uuid.UUID(value))
  
subject: Enable cache_ok on custom sqlalchemy UUID type