def _to_yaml_list()

in src/datasets/features/features.py [0:0]

• 48 lines of code
• 26 McCabe index (conditional complexity)

    def _to_yaml_list(self) -> list:
        # we compute the YAML list from the dict representation that is used for JSON dump
        yaml_data = self.to_dict()

        def simplify(feature: dict) -> dict:
            if not isinstance(feature, dict):
                raise TypeError(f"Expected a dict but got a {type(feature)}: {feature}")

            for list_type in ["large_list", "list", "sequence"]:
                #
                # list_type:                ->              list_type: int32
                #   dtype: int32            ->
                #
                if isinstance(feature.get(list_type), dict) and list(feature[list_type]) == ["dtype"]:
                    feature[list_type] = feature[list_type]["dtype"]

                #
                # list_type:                ->              list_type:
                #   struct:                 ->              - name: foo
                #   - name: foo             ->                dtype: int32
                #     dtype: int32          ->
                #
                if isinstance(feature.get(list_type), dict) and list(feature[list_type]) == ["struct"]:
                    feature[list_type] = feature[list_type]["struct"]

            #
            # class_label:              ->              class_label:
            #   names:                  ->                names:
            #   - negative              ->                  '0': negative
            #   - positive              ->                  '1': positive
            #
            if isinstance(feature.get("class_label"), dict) and isinstance(feature["class_label"].get("names"), list):
                # server-side requirement: keys must be strings
                feature["class_label"]["names"] = {
                    str(label_id): label_name for label_id, label_name in enumerate(feature["class_label"]["names"])
                }
            return feature

        def to_yaml_inner(obj: Union[dict, list]) -> dict:
            if isinstance(obj, dict):
                _type = obj.pop("_type", None)
                if _type == "LargeList":
                    _feature = obj.pop("feature")
                    return simplify({"large_list": to_yaml_inner(_feature), **obj})
                elif _type == "List":
                    _feature = obj.pop("feature")
                    return simplify({"list": to_yaml_inner(_feature), **obj})
                elif _type == "Value":
                    return obj
                elif _type and not obj:
                    return {"dtype": camelcase_to_snakecase(_type)}
                elif _type:
                    return {"dtype": simplify({camelcase_to_snakecase(_type): obj})}
                else:
                    return {"struct": [{"name": name, **to_yaml_inner(_feature)} for name, _feature in obj.items()]}
            elif isinstance(obj, list):
                return simplify({"list": simplify(to_yaml_inner(obj[0]))})
            elif isinstance(obj, tuple):
                return to_yaml_inner(list(obj))
            else:
                raise TypeError(f"Expected a dict or a list but got {type(obj)}: {obj}")

        def to_yaml_types(obj: dict) -> dict:
            if isinstance(obj, dict):
                return {k: to_yaml_types(v) for k, v in obj.items()}
            elif isinstance(obj, list):
                return [to_yaml_types(v) for v in obj]
            elif isinstance(obj, tuple):
                return to_yaml_types(list(obj))
            else:
                return obj

        return to_yaml_types(to_yaml_inner(yaml_data)["struct"])