[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