code: def execute_migration(self, migration_file_relative):
          
          migration_file = os.path.join(self.db_config['migrations_dir'], migration_file_relative)
          m_type = self.repository.migration_type(migration_file)
          if m_type == 'native':
              return self.execute_native_migration(migration_file)
          if m_type == 'py':
              module = imp.load_source('migration_module', migration_file)
              return self.execute_python_migration(migration_file, module)
          assert False, 'Unknown migration type %s' % migration_file
docs: This recognizes migration type and executes either
          :method:`execute_python_migration` or :method:`execute_native_migration`