code: def temporary_key(d, key, value):
      
      d[key] = value
      try:
          yield d
      finally:
          del d[key]
docs: Context manager that removes key from dictionary on closing
  
      The dictionary will hold the key for the duration of
      the context.
  
      Parameters
      ----------
      d : dict-like
          Dictionary in which to insert a temporary key.
      key : hashable
          Location at which to insert ``value``.
      value : object
          Value to insert in ``d`` at location ``key``.