LRUCache.py

# ref: https://www.geeksforgeeks.org/lru-cache-in-python-using-ordereddict/
from collections import OrderedDict


class LRUCache:
    def __init__(self, capacity):
        self.cache = OrderedDict()
        self.capacity = capacity

    def get(self, k):
        if k not in self.cache:
            return -1
        else:
            self.cache.move_to_end(k)
            return self.cache[k]

    def put(self, k, v):
        self.cache[k] = v
        self.cache.move_to_end(k)
        if len(self.cache) > self.capacity:
            self.cache.popitem(last=False)  # pop first item


if __name__ == '__main__':
    cache = LRUCache(2)
    cache.put(1, 1)
    print(cache.cache)
    cache.put(2, 2)
    print(cache.cache)
    cache.get(1)
    print(cache.cache)
    cache.put(3, 3)
    print(cache.cache)
    cache.get(2)
    print(cache.cache)
    cache.put(4, 4)
    print(cache.cache)
    cache.get(1)
    print(cache.cache)
    cache.get(3)
    print(cache.cache)
    cache.get(4)
    print(cache.cache)