Build your own cache in Python

Caching or memoization is the act of storing calculated results in order to avoid having to calculate them again. In Python we have the @cache decorator in the functools module. But I figured it would be fun to write my own. I know it's silly but its also fun to see how a simple implementation of a cache actually works... Its basically just a dictionary with the function name plus its parameters as the key looking up the calculated value.

@my_cache

cache = {}

def my_cache(func):
    def wrapper(*args, **kwargs):
        key = f'{func.__name__}-{args}-{kwargs}'
        if key in cache:
            return cache[key]
        result = func(*args, **kwargs)
        cache[key] = result
        return result
    return wrapper

# How to use it
@my_cache
def try_my_cache(*args, **kwargs):
    time.sleep(3)
    return 'This result will just have to wait 3 seconds once.'