bazarr/libs/bidict/_frozenbidict.py

52 lines
2.3 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2009-2019 Joshua Bronson. All Rights Reserved.
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#==============================================================================
# * Welcome to the bidict source code *
#==============================================================================
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# ← Prev: _delegating_mixins.py Current: _frozenbidict.py Next: _mut.py →
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"""Provides :class:`frozenbidict`, an immutable, hashable bidirectional mapping type."""
from ._base import BidictBase
from ._delegating_mixins import _DelegateKeysAndItemsToFwdm
from .compat import ItemsView
class frozenbidict(_DelegateKeysAndItemsToFwdm, BidictBase): # noqa: N801,E501; pylint: disable=invalid-name
"""Immutable, hashable bidict type."""
__slots__ = ()
def __hash__(self): # lgtm [py/equals-hash-mismatch]
"""The hash of this bidict as determined by its items."""
if getattr(self, '_hash', None) is None:
# pylint: disable=protected-access,attribute-defined-outside-init
self._hash = ItemsView(self)._hash()
return self._hash
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