class_docstr: Variant of ChainMap that allows direct updates to inner scopes.
  
  Only works when all passed mapping are mutable.
class_docstr_tok: ["Variant","of","ChainMap","that","allows","direct","updates","to","inner","scopes",".","Only","works","when","all","passed","mapping","are","mutable","."]
docstr: Raises
  ------
  KeyError
      If `key` doesn't exist.
docstr_tok: ["Raises","--","--","--","KeyError","If","`","key","`","does","n't","exist","."]
code: def __delitem__(self, key: _KT) -> None:
      """
      Raises
      ------
      KeyError
          If `key` doesn't exist.
      """
      for mapping in self.maps:
          if key in mapping:
              del mapping[key]
              return
      raise KeyError(key)
  
imports: from __future__ import annotations
  import datetime
  import inspect
  from io import StringIO
  import itertools
  import pprint
  import struct
  import sys
  from typing import ChainMap, TypeVar
  import numpy
  from pandas._libs.tslibs import Timestamp
  from pandas.errors import UndefinedVariableError
label_desc: Use image node_id 2 for calling the DeepChainMap obj's underlying member method code with example usage: obj.__delitem__(key) without return types