在数据类变量中允许多种数据类型

Question

Is there a way to allow a dataclass variable to have one of multiple data types? (And it should also work in Python 3.7)

@dataclass
class C:
    index_range: tuple or str = "all"

I want index_range to have the default value string "all" , but also the possibility to take a tuple as a value. (Later in the function I define that "all" means that all indices are used, but if a tuple is given only the elements between these numbers are used.)

Pylance always gives me the error that "all" is not a Tuple .

Are also more than two types possible, like tuple or None or str?

Answer 1

You're looking for the typing.Union :

from typing import Union


@dataclass
class C:
    index_range: Union[tuple, str] = "all"