forked from varia/varia.website
40 lines
1.2 KiB
Python
40 lines
1.2 KiB
Python
"""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)
|