214 class lrucachedict(object):

   215     '''cache most recent gets from or sets to this dictionary'''

   216     def __init__(self, maxsize):

   217         self._cache = {}

   218         self._maxsize = maxsize

   219         self._order = deque()

   220 

   221     def __getitem__(self, key):

   222         value = self._cache[key]

   223         self._order.remove(key)

   224         self._order.append(key)

   225         return value

   226 

   227     def __setitem__(self, key, value):

   228         if key not in self._cache:

   229             if len(self._cache) >= self._maxsize:

   230                 del self._cache[self._order.popleft()]

   231         else:

   232             self._order.remove(key)

   233         self._cache[key] = value

   234         self._order.append(key)

   235 

   236     def __contains__(self, key):

   237         return key in self._cache

   238