How do I cache expensive computations in Python?

# Example of caching expensive computations using functools.lru_cache
from functools import lru_cache
import time

@lru_cache(maxsize=None)  # Unlimited cache size
def expensive_computation(n):
    time.sleep(2)  # Simulate a time-consuming computation
    return n * n

# First call will take time
print(expensive_computation(4))  # Output: 16

# Subsequent call will be fast as it is cached
print(expensive_computation(4))  # Output: 16
print(expensive_computation(5))  # Output: 25
print(expensive_computation(5))  # Output: 25