"""Utilities for defining models """ import operator from typing import Any, Callable, Type class KeyBasedCompareMixin: """Provides comparison capabilities that is based on a key""" __slots__ = ["_compare_key", "_defining_class"] def __init__(self, key: Any, defining_class: Type["KeyBasedCompareMixin"]) -> None: self._compare_key = key self._defining_class = defining_class def __hash__(self) -> int: return hash(self._compare_key) def __lt__(self, other: Any) -> bool: return self._compare(other, operator.__lt__) def __le__(self, other: Any) -> bool: return self._compare(other, operator.__le__) def __gt__(self, other: Any) -> bool: return self._compare(other, operator.__gt__) def __ge__(self, other: Any) -> bool: return self._compare(other, operator.__ge__) def __eq__(self, other: Any) -> bool: return self._compare(other, operator.__eq__) def _compare(self, other: Any, method: Callable[[Any, Any], bool]) -> bool: if not isinstance(other, self._defining_class): return NotImplemented return method(self._compare_key, other._compare_key)