parameters: (self, key)
return_statement: return rv
docstring: Get an item from the cache. Moves the item up so that it has the
          highest priority then.
  
          Raise an `KeyError` if it does not exist.
docstring_summary: Get an item from the cache. Moves the item up so that it has the
          highest priority then.
docstring_tokens: Get an item from the cache . Moves the item up so that it has the highest priority then .
function: def __getitem__(self, key):
          """Get an item from the cache. Moves the item up so that it has the
          highest priority then.
  
          Raise an `KeyError` if it does not exist.
          """
          rv = self._mapping[key]
          if self._queue[-1] != key:
              try:
                  self._remove(key)
              except ValueError:
                  # if something removed the key from the container
                  # when we read, ignore the ValueError that we would
                  # get otherwise.
                  pass
              self._append(key)
          return rv
function_tokens: def __getitem__ ( self , key ) : rv = self . _mapping [ key ] if self . _queue [ - 1 ] != key : try : self . _remove ( key ) except ValueError : # if something removed the key from the container # when we read, ignore the ValueError that we would # get otherwise. pass self . _append ( key ) return rv