How can I implement an LRU cache in Python?

How can I implement an LRU cache in Python?

You can implement an LRU (Least Recently Used) cache in Python using the collections.OrderedDict class. Would you like a code example?

Yes, please provide a code example.

Here's a simple implementation:

from collections import OrderedDict

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

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

    def put(self, key: int, value: int) -> None:
        if key in self.cache:
            self.cache.move_to_end(key)
        self.cache[key] = value
        if len(self.cache) > self.capacity:
            self.cache.popitem(last=False)

How does this implementation handle cache eviction?

The implementation evicts the least recently used item when the cache exceeds its capacity by using popitem(last=False), which removes the first item in the ordered dictionary.