In case you were wondering, Python’s built-in LRU cache function decorator doesn’t cache function calls with the same keyword arguments written in a different order. That is, if you cache a function and then call it twice, with the same keyword arguments but written in a different order, on the second call you won’t get the cached result and the function will be re-run.
Let’s construct an example. We’re interested in keyword arguments, so we’ll make our function only take keyword arguments (1). We want some side-effect to tell us whether it was a cache hit or miss, so we’ll print each keyword when we iterate over it (2). We want to cache a result, so we’ll return the sum of the values of the keyword arguments (3). Finally, we apply the lru_cache decorator to the function with a maxsize=None to let the cache grow unbounded. Putting all that together, we get:
