1# Copyright 2021 The TensorFlow Authors. All Rights Reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14# ============================================================================== 15"""Immutable mapping.""" 16 17import collections.abc 18 19 20# WARNING: this class is used internally by extension types (tf.ExtensionType), 21# and may be deleted if/when extension types transition to a different encoding 22# in the future. 23class ImmutableDict(collections.abc.Mapping): 24 """Immutable `Mapping`.""" 25 # Note: keys, items, values, get, __eq__, and __ne__ are implemented by 26 # the `Mapping` base class. 27 28 def __init__(self, *args, **kwargs): 29 self._dict = dict(*args, **kwargs) 30 31 def __getitem__(self, key): 32 return self._dict[key] 33 34 def __contains__(self, key): 35 return key in self._dict 36 37 def __iter__(self): 38 return iter(self._dict) 39 40 def __len__(self): 41 return len(self._dict) 42 43 def __repr__(self): 44 return f'ImmutableDict({self._dict})' 45