autocast.py

def autocast(func):
    """Tries to cast any parameters with type hints to the type defined.
        Will not act if more than one type is defined.

        Try to avoid using this, instead type-cast within your function to the desired types."""

    def autocast_wrapper(*args, **kwargs):
        sig = signature(func)

        def convert(arg, param):
            try:
                annotation = sig.parameters[param].annotation
            except KeyError:
                annotation = _empty

            # magic
            if annotation is not _empty and annotation.__class__ is type:
                if not isinstance(arg, annotation):
                    return annotation(arg)
            return arg

        new_args = [convert(arg, param) for arg, param in zip(args, sig.parameters)]
        new_kwargs = {param: convert(arg, param) for param, arg in kwargs.items()}

        return func(*new_args, **new_kwargs)

    return autocast_wrapper

### Example usage
@autocast
def on_deal(self, card: Card, offset: int) -> bool:
    board = self.board
    board.append(card)
    self.board[-1 if offset is None else offset] = board
    self.on_record_action()
    return true