Since Python 3.3 a bug was fixed meaning the property() decorator is now correctly identified as abstract when applied to an abstract method.

Note: Order matters, you have to use @property above @abstractmethod

Python 3.3+: (python docs):

from abc import ABC, abstractmethod

class C(ABC):
    @property
    @abstractmethod
    def my_abstract_property(self):
        ...

Python 2: (python docs)

from abc import ABCMeta, abstractproperty

class C:
    __metaclass__ = ABCMeta

    @abstractproperty
    def my_abstract_property(self):
        ...

import abc
from typing import ClassVar

from pydantic import BaseModel
from devtools import debug

class Fruit(BaseModel, abc.ABC):
    @property
    @abc.abstractmethod
    def type(self) -> str:
        """The name of the type of fruit."""

class Apple(Fruit):
    type: ClassVar[str] = "apple"
    size: int

a = Apple(size=4)
debug(a, a.type)

Unless you want to allow type to be changed when creating a model instance, in which case just make it a field on Fruit.