item – Complex Extractor for data extracting.

class data_extractor.item.Field(extractor: AbstractSimpleExtractor | None = None, name: str | None = None, default: Any = sentinel, is_many: bool = False, type: Type[RV] | None = None, convertor: Callable[[Any], RV] | None = None)

Bases: Generic[RV], AbstractComplexExtractor

Extract data by cooperating with extractor.

Parameters:

• extractor (data_extractor.core.AbstractSimpleExtractor) – The object for data extracting

• name (str, optional) – Optional parameter for special field name.

• default (Any) – Default value when not found. Default: data_extractor.utils.sentinel.

• is_many (bool) – Indicate the data which extractor extracting is more than one.

Raises:

• ValueError – Invalid SimpleExtractor.

• ValueError – Can’t both set default and is_manay=True.

extract(element: Any) → RV | List[RV]

Extract the wanted data.

Parameters:

element (Any) – The target data node element.

Returns:

Data or subelement.

Return type:

Any

Raises:

ExtractError – Thrown by extractor extracting wrong data.

class data_extractor.item.Item(extractor=None, name=None, default=sentinel, is_many=False, type=None, convertor=None)

Bases: Field

Extract data by cooperating with extractors, fields and items.

extract(element: Any) → RV | List[RV]

Extract the wanted data.

Parameters:

element (Any) – The target data node element.

Returns:

Data or subelement.

Return type:

Any

Raises:

ExtractError – Thrown by extractor extracting wrong data.

classmethod field_names() → Iterator[str]

Iterate all Item or Field type attributes’ name.

simplify() → AbstractSimpleExtractor

Create an extractor that has compatible API like SimpleExtractor’s.

Returns:

A simple extractor.

Return type:

data_extractor.core.AbstractSimpleExtractor