Module aws_lambda_powertools.utilities.idempotency.serialization.functions

Functions

def get_actual_type(model_type: Any) ‑> Any

Expand source code

def get_actual_type(model_type: Any) -> Any:
    """
    Extract the actual type from a potentially Optional or Union type.
    This function handles types that may be wrapped in Optional or Union,
    including the Python 3.10+ Union syntax (Type | None).
    Parameters
    ----------
    model_type: Any
        The type to analyze. Can be a simple type, Optional[Type], BaseModel, dataclass
    Returns
    -------
    The actual type without Optional or Union wrappers.
    Raises:
        IdempotencyModelTypeError: If the type specification is invalid
                                   (e.g., Union with multiple non-None types).
    """

    # Get the origin of the type (e.g., Union, Optional)
    origin = get_origin(model_type)

    # Check if type is Union, Optional, or UnionType (Python 3.10+)
    if origin in (Union, Optional) or (sys.version_info >= (3, 10) and origin in (Union, UnionType)):
        # Get type arguments
        args = get_args(model_type)

        # Filter out NoneType
        actual_type = _extract_non_none_types(args)

        # Ensure only one non-None type exists
        if len(actual_type) != 1:
            raise IdempotencyModelTypeError(
                "Invalid type: expected a single type, optionally wrapped in Optional or Union with None.",
            )

        return actual_type[0]

    # If not a Union/Optional type, return original type
    return model_type

Extract the actual type from a potentially Optional or Union type. This function handles types that may be wrapped in Optional or Union, including the Python 3.10+ Union syntax (Type | None). Parameters

---

model_type : Any

The type to analyze. Can be a simple type, Optional[Type], BaseModel, dataclass

Returns

The actual type without Optional or Union wrappers.

Raises

IdempotencyModelTypeError

If the type specification is invalid (e.g., Union with multiple non-None types).