[Python] How to associate a literal label with a type and extract it to define another type in...

I’m trying to associate a string label with each class and then use those labels to define a Literal type for validation or type checking purposes. Here’s a simplified example of what I’m trying to do:

from typing import Literal

class Apple:
label = "apple"

class Mango:
label = "mango"

# I'd like to define this type using the class labels above:
type FruitName = Literal[Apple.label, Mango.label]


This doesn’t work because Literal expects constant string values at type-check time, but Apple.label and Mango.label are not treated as constants.

Mypy error: Parameter 1 of Literal[...] is invalid [valid-type]

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