Is it possible to use *args in a dataclass?

python, python-3.x, python-dataclasses

Solution

I see in the PEP an example of how to override the `__init__`.

Sometimes the generated init method does not suffice. For example, suppose you wanted to have an object to store *args and **kwargs:

@dataclass(init=False)
class ArgHolder:
    args: List[Any]
    kwargs: Mapping[Any, Any]

    def __init__(self, *args, **kwargs):
        self.args = args
        self.kwargs = kwargs

a = ArgHolder(1, 2, three=3)

Problem

I recently started using dataclasses and they will be a nice addition to 3.7. I'm curious if or how it is possible to recreate the same functionality of this class using dataclasses. ``` class Nav(object): def __init__(self, name:str, menu, page, *submenus): self.name = name self.menu = menu self.page = page self.submenus = submenus foo = Nav("name", "menu", "page") ``` This doesn't work. Raises Exception `TypeError: __init__() missing 1 required positional argument: 'submenus'` ``` @dataclass class Nav(object): name:str menu: Any page: Any submenus: tuple foo = Nav("name", "menu", "page") ``` I assume this is because the class doesn't have the instructions to do the unpacking of the arguments. Is there some way to instruct the dataclass decorator that submenus needs to be unpacked?

Original source