Viewing file:  models.py (1.17 KB) -rw-r--r--
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"""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)
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