abcattrs

Abstract class attributes for ABCs.

Examples

import abc
from abcattrs import abstractattrs, Abstract


@abstractattrs
class A(abc.ABC):
    foo: Abstract[int]


# Abstract subclasses can add more required attributes.
class B(A, abc.ABC):
    bar: Abstract[str]


class C(B):
    # C must assign values to both of these attributes to not raise an error.
    foo = 1
    bar = "str"


# This raises an error.
class MissingBar(B):
    foo = 1


# This raises an error.
class MissingFoo(B):
    bar = "str"

The Abstract qualifier can be combined with other PEP 593 annotations.

from typing import Annotated
import abc
from abcattrs import abstractattrs, Abstract


@abstractattrs
class A(abc.ABC):
    # Combine with other annotations
    bar: Annotated[str, Abstract, "other info"]