code: def select(self, sql_string, cols, *args, **kwargs):
          
          working_columns = None
          if kwargs.get('columns') is not None:
              working_columns = kwargs.pop('columns')
          query = self._assemble_select(sql_string, cols, *args, *kwargs)
          return self._execute(query, working_columns=working_columns)
docs: Execute a SELECT statement 
  
          :sql_string:    An SQL string template
          :columns:       A list of columns to be returned by the query
          :*args:         Arguments to be passed for query parameters.
          :returns:       Psycopg2 result