Serialization API (core.serialization)¶

def from_dict(
    transform_dict: Dict[str, Any],
    nonserializable: Optional[Dict[str, Any]] = None,
) -> Optional[Serializable]:
    """Args:
    transform_dict: A dictionary with serialized transform pipeline.
    nonserializable (dict): A dictionary that contains non-serializable transforms.
        This dictionary is required when you are restoring a pipeline that contains non-serializable transforms.
        Keys in that dictionary should be named same as `name` arguments in respective transforms from
        a serialized pipeline.

    """
    register_additional_transforms()
    transform = transform_dict["transform"]
    lmbd = instantiate_nonserializable(transform, nonserializable)
    if lmbd:
        return lmbd
    name = transform["__class_fullname__"]
    args = {k: v for k, v in transform.items() if k != "__class_fullname__"}
    cls = SERIALIZABLE_REGISTRY[shorten_class_name(name)]
    if "transforms" in args:
        args["transforms"] = [from_dict({"transform": t}, nonserializable=nonserializable) for t in args["transforms"]]
    return cls(**args)

def get_shortest_class_fullname(cls: Type[Any]) -> str:
    """The function `get_shortest_class_fullname` takes a class object as input and returns its shortened
    full name.

    :param cls: The parameter `cls` is of type `Type[BasicCompose]`, which means it expects a class that
    is a subclass of `BasicCompose`
    :type cls: Type[BasicCompose]
    :return: a string, which is the shortened version of the full class name.
    """
    class_fullname = f"{cls.__module__}.{cls.__name__}"
    return shorten_class_name(class_fullname)

def load(
    filepath_or_buffer: Union[str, Path, TextIO],
    data_format: str = "json",
    nonserializable: Optional[Dict[str, Any]] = None,
) -> object:
    """Load a serialized pipeline from a file or file-like object and construct a transform pipeline.

    Args:
        filepath_or_buffer (Union[str, Path, TextIO]): The file path or file-like object to read the serialized
            data from.
            If a string is provided, it is interpreted as a path to a file. If a file-like object is provided,
            the serialized data will be read from it directly.
        data_format (str): The format of the serialized data. Valid options are 'json' and 'yaml'.
            Defaults to 'json'.
        nonserializable (Optional[Dict[str, Any]]): A dictionary that contains non-serializable transforms.
            This dictionary is required when restoring a pipeline that contains non-serializable transforms.
            Keys in the dictionary should be named the same as the `name` arguments in respective transforms
            from the serialized pipeline. Defaults to None.

    Returns:
        object: The deserialized transform pipeline.

    Raises:
        ValueError: If `data_format` is 'yaml' but PyYAML is not installed.

    """
    check_data_format(data_format)

    if isinstance(filepath_or_buffer, (str, Path)):  # Assume it's a filepath
        with open(filepath_or_buffer) as f:
            if data_format == "json":
                transform_dict = json.load(f)
            else:
                if not yaml_available:
                    msg = "You need to install PyYAML to load a pipeline in yaml format"
                    raise ValueError(msg)
                transform_dict = yaml.safe_load(f)
    elif data_format == "json":
        transform_dict = json.load(filepath_or_buffer)
    else:
        if not yaml_available:
            msg = "You need to install PyYAML to load a pipeline in yaml format"
            raise ValueError(msg)
        transform_dict = yaml.safe_load(filepath_or_buffer)

    return from_dict(transform_dict, nonserializable=nonserializable)

def register_additional_transforms() -> None:
    """Register transforms that are not imported directly into the `albumentations` module by checking
    the availability of optional dependencies.
    """
    if importlib.util.find_spec("torch") is not None:
        try:
            # Import `albumentations.pytorch` only if `torch` is installed.
            import albumentations.pytorch

            # Use a dummy operation to acknowledge the use of the imported module and avoid linting errors.
            _ = albumentations.pytorch.ToTensorV2
        except ImportError:
            pass

def save(
    transform: "Serializable",
    filepath_or_buffer: Union[str, Path, TextIO],
    data_format: str = "json",
    on_not_implemented_error: str = "raise",
) -> None:
    """Serialize a transform pipeline and save it to either a file specified by a path or a file-like object
    in either JSON or YAML format.

    Args:
        transform (Serializable): The transform pipeline to serialize.
        filepath_or_buffer (Union[str, Path, TextIO]): The file path or file-like object to write the serialized
            data to.
            If a string is provided, it is interpreted as a path to a file. If a file-like object is provided,
            the serialized data will be written to it directly.
        data_format (str): The format to serialize the data in. Valid options are 'json' and 'yaml'.
            Defaults to 'json'.
        on_not_implemented_error (str): Determines the behavior if a transform does not implement the `to_dict` method.
            If set to 'raise', a `NotImplementedError` is raised. If set to 'warn', the exception is ignored, and
            no transform arguments are saved. Defaults to 'raise'.

    Raises:
        ValueError: If `data_format` is 'yaml' but PyYAML is not installed.

    """
    check_data_format(data_format)
    transform_dict = transform.to_dict(on_not_implemented_error=on_not_implemented_error)
    transform_dict = serialize_enum(transform_dict)

    # Determine whether to write to a file or a file-like object
    if isinstance(filepath_or_buffer, (str, Path)):  # It's a filepath
        with open(filepath_or_buffer, "w") as f:
            if data_format == "yaml":
                if not yaml_available:
                    msg = "You need to install PyYAML to save a pipeline in YAML format"
                    raise ValueError(msg)
                yaml.safe_dump(transform_dict, f, default_flow_style=False)
            elif data_format == "json":
                json.dump(transform_dict, f)
    elif data_format == "yaml":
        if not yaml_available:
            msg = "You need to install PyYAML to save a pipeline in YAML format"
            raise ValueError(msg)
        yaml.safe_dump(transform_dict, filepath_or_buffer, default_flow_style=False)
    elif data_format == "json":
        json.dump(transform_dict, filepath_or_buffer)

def serialize_enum(obj: Any) -> Any:
    """Recursively search for Enum objects and convert them to their value.
    Also handle any Mapping or Sequence types.
    """
    if isinstance(obj, Mapping):
        return {k: serialize_enum(v) for k, v in obj.items()}
    if isinstance(obj, Sequence) and not isinstance(obj, str):  # exclude strings since they're also sequences
        return [serialize_enum(v) for v in obj]
    return obj.value if isinstance(obj, Enum) else obj

def to_dict(transform: Serializable, on_not_implemented_error: str = "raise") -> Dict[str, Any]:
    """Take a transform pipeline and convert it to a serializable representation that uses only standard
    python data types: dictionaries, lists, strings, integers, and floats.

    Args:
        transform: A transform that should be serialized. If the transform doesn't implement the `to_dict`
            method and `on_not_implemented_error` equals to 'raise' then `NotImplementedError` is raised.
            If `on_not_implemented_error` equals to 'warn' then `NotImplementedError` will be ignored
            but no transform parameters will be serialized.
        on_not_implemented_error (str): `raise` or `warn`.

    """
    return transform.to_dict(on_not_implemented_error)