[LeetCode]题解（python）：146-LRU Cache

题目来源：

　　https://leetcode.com/problems/lru-cache/

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实现一个LRU缓存。直接上代码。

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代码（python）：

 class LRUCache(object):

     def __init__(self, capacity):
         """
         :type capacity: int
         """
         LRUCache.capacity = capacity
         LRUCache.length = 0
         LRUCache.dict = collections.OrderedDict()

     def get(self, key):
         """
         :rtype: int
         """
         try:
             value = LRUCache.dict[key]
             del LRUCache.dict[key]
             LRUCache.dict[key] = value
             return value
         except:
             return -1

     def set(self, key, value):
         """
         :type key: int
         :type value: int
         :rtype: nothing
         """
         try:
             del LRUCache.dict[key]
             LRUCache.dict[key] = value
         except:
             if LRUCache.length == LRUCache.capacity:
                 LRUCache.dict.popitem(last = False)
                 LRUCache.length -= 1
             LRUCache.dict[key] = value
             LRUCache.length += 1