"""Utilities for defining models """ # The following comment should be removed at some point in the future. # mypy: disallow-untyped-defs=False import operator class KeyBasedCompareMixin(object): """Provides comparison capabilities that is based on a key """ def __init__(self, key, defining_class): self._compare_key = key self._defining_class = defining_class def __hash__(self): return hash(self._compare_key) def __lt__(self, other): return self._compare(other, operator.__lt__) def __le__(self, other): return self._compare(other, operator.__le__) def __gt__(self, other): return self._compare(other, operator.__gt__) def __ge__(self, other): return self._compare(other, operator.__ge__) def __eq__(self, other): return self._compare(other, operator.__eq__) def __ne__(self, other): return self._compare(other, operator.__ne__) def _compare(self, other, method): if not isinstance(other, self._defining_class): return NotImplemented return method(self._compare_key, other._compare_key)