asdict

asdict is a function from Python's standard library dataclasses module. It returns a dictionary representation of a dataclass instance by recursively converting its fields to dictionaries when appropriate. The function requires a dataclass instance and will raise a TypeError if given a non-dataclass object.

When applied to a dataclass, asdict includes each field in the output dictionary under its field name. If a field value is itself a dataclass, asdict recursively converts it to a dictionary. If a field is a list, tuple, or dictionary, its contents are processed recursively as well. The function accepts an optional dict_factory argument to customize the type of dictionaries created; by default it uses the built-in dict.

asdict is commonly used to prepare dataclass data for serialization, such as JSON encoding, since a dataclass instance is not directly JSON-serializable. However, it does not guarantee that all values will be JSON serializable; non-serializable objects may require further processing.

Some practical notes: asdict preserves a deep copy-like behavior for dataclass structures, producing new dicts and containers rather than referencing the original objects. It also handles recursive references to avoid infinite loops during conversion. The function is part of Python 3.7 and later. There is a related concept in third-party libraries (for example, attrs provides a similar asdict) but the standard library version is the most commonly used approach for native dataclasses.