LRU caching using python

lruCachingPython.py

class Caching:
    def __init__(self, size=5):
        self.store = {}
        self.size = 5

    def update_recently_used(self, key):
        value = self.store.pop(key)
        self.store[key] = value

    def get(self, key):
        value = self.store.get(key, 'Not Found')
        if value != 'Not Found':
            self.update_recently_used(key)
        return value

    def insert(self, key, value):
        exists = self.get(key)
        self.store[key] = value
        if exists == 'Not Found':
            self.delete_least_used()

    def delete_least_used(self):
        all_keys = list(self.store.keys())
        if len(all_keys) > self.size:
            self.store.pop(all_keys[0])

    def delete(self, key):
        self.store.pop(key, None)

    def update(self, key, value):
        exists = self.get(key)
        if exists == 'Not Found':
            return 'NF'
        self.store[key] = value

    def get_all_values(self):
        return self.store




cach = Caching()

print(cach.insert(1, 'a'))
print(cach.store)
print(cach.insert(2, 'b'))
print(cach.store)
print(cach.insert(3, 'c'))
print(cach.store)
print(cach.insert(4, 'd'))
print(cach.store)
print(cach.insert(5, 'e'))
print(cach.store)
cach.insert(6, 'f')
print(cach.store)
print(cach.get(2))
print(cach.store)
print(cach.insert(6, 'f'))
print(cach.store)
print(cach.update(5, 'ee'))
print(cach.store)
print(cach.delete(3))
print(cach.store)