def normalize_map_join()

in python-package/lets_plot/plot/util.py [0:0]

• 35 lines of code
• 14 McCabe index (conditional complexity)

def normalize_map_join(map_join):
    if map_join is None:
        return None

    def invalid_map_join_format():
        return ValueError("map_join must be a str, list[str] or pair of list[str]")

    if isinstance(map_join, str):  # 'foo' -> [['foo'], None]
        data_names = [map_join]
        map_names = None
    elif isinstance(map_join, Sequence):
        if all(isinstance(v, str) for v in map_join):  # all items are strings
            if len(map_join) == 1:  # ['foo'] -> [['foo'], None]
                data_names = map_join
                map_names = None
            elif len(map_join) == 2:  # ['foo', 'bar'] -> [['foo'], ['bar']]
                data_names = [map_join[0]]
                map_names = [map_join[1]]
            elif len(map_join) > 2:  # ['foo', 'bar', 'baz'] -> error
                raise ValueError(
                    "map_join of type list[str] expected to have 1 or 2 items, but was {}".format(len(map_join)))
            else:
                raise invalid_map_join_format()
        elif all(isinstance(v, Sequence) and not isinstance(v, str) for v in map_join):  # all items are lists
            if len(map_join) == 1:  # [['foo', 'bar']] -> [['foo', 'bar'], None]
                data_names = map_join[0]
                map_names = None
            elif len(map_join) == 2:  # [['foo', 'bar'], ['baz', 'qux']] -> [['foo', 'bar'], ['baz', 'qux']]
                data_names = map_join[0]
                map_names = map_join[1]
            else:
                raise invalid_map_join_format()
        else:
            raise invalid_map_join_format()

    else:
        raise invalid_map_join_format()

    return [data_names, map_names]