code: def convertall(table, *args, **kwargs):
      
  
      # TODO don't read the data twice!
      return convert(table, header(table), *args, **kwargs)
docs: Convenience function to convert all fields in the table using a common
      function or mapping. See also :func:`convert`.
  
      The ``where`` keyword argument can be given with a callable or expression
      which is evaluated on each row and which should return True if the
      conversion should be applied on that row, else False.