from functools import lru_cache

@lru_cache(maxsize=10)
def add(a, b):
    print('add method called')
    return a+b

print(add(7, 4))

add method called
11

print(add(7, 4))

11

print(add(5, 2))

add method called
7

print(add(5, 2))

7

# clear cache
add.cache_clear()

print(add(5, 2))

add method called
7

print(add(5, 2))

7