item – Complex Extractor for data extracting.

class data_extractor.item.Field(extractor: data_extractor.core.AbstractSimpleExtractor = None, name: str = None, default: Any = sentinel, is_many: bool = False)

Bases: data_extractor.core.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) → Any

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: data_extractor.core.AbstractSimpleExtractor = None, name: str = None, default: Any = sentinel, is_many: bool = False)

Bases: data_extractor.item.Field

Extract data by cooperating with extractors, fields and items.

extract(element: Any) → Any

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() → data_extractor.core.AbstractSimpleExtractor

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

Returns

A simple extractor.

Return type

data_extractor.core.AbstractSimpleExtractor