docs: def _is_valid_options_weights_list(value):
      '''Check whether ``values`` is a valid argument for ``weighted_choice``.'''
      return ((isinstance(value, list)) and
              len(value) > 1 and
              (all(isinstance(opt, tuple) and
                   len(opt) == 2 and
                   isinstance(opt[1], (int, float))
                   for opt in value)))