Class LRUCache

object --+    
         |    
      dict --+
             |
            LRUCache

A dictionary-like object that stores only a certain number of items, and discards its least recently used item when full.

>>> cache = LRUCache(3)
>>> cache['A'] = 0
>>> cache['B'] = 1
>>> cache['C'] = 2
>>> len(cache)
3

>>> cache['A']
0

Adding new items to the cache does not increase its size. Instead, the least recently used item is dropped:

>>> cache['D'] = 3
>>> len(cache)
3
>>> 'B' in cache
False

Iterating over the cache returns the keys, starting with the most recently used:

>>> for key in cache:
...     print(key)
D
A
C

This code is based on the LRUCache class from myghtyutils.util, written by Mike Bayer and released under the MIT license. See:

http://svn.myghty.org/myghtyutils/trunk/lib/myghtyutils/util.py

new empty dictionary