dataclass-abc 0.0.1

Library that lets you define abstract properties in dataclasses.

Dataclass ABC

Library that lets you define abstract properties in dataclasses.

Installation

pip install dataclass-abc

Usage

from abc import ABC, abstractmethod
from dataclasses import dataclass

from dataclass_abc import resolve_abc_prop

class A(ABC):
    @property
    @abstractmethod
    def val(self) -> str:
        ...

@resolve_abc_prop
@dataclass
class B(A):
    val: str

Example

The example takes some code snippets from https://realpython.com/python-data-classes/ and implements them with abstract properties.

Design pattern

This library suggests the design pattern as implemented in the example:

• mixins - a mixin is an abstract class that implements data as abstract properties and methods based on the abstract properties.
• classes - an abstract class inherits from one or more mixins (see City or CapitalCity in the example). This class is used for pattern matching, e.g. using isinstance method.
• impl - an implementation class implements the abstract properties. (see CityImpl or CapitalCityImpl in the example). This class is decorated with dataclass and resolve_abc_prop and should always be called through an initialize function.
• init - initialize functions (or constructor functions) initialize an implementation class.