A minor but useful recent addition to Python’s syntax, positional-only parameters, lets you indicate which function parameters must be specified as positional ones, never as keyword arguments.

Function keys are the F1-F12 keys that run across the top of your keyboard. Commonly ignored yet incredibly useful, most function keys act as time-saving, shortcut buttons.

To memoize a function in Python, we can use a utility supplied in Python’s standard library—the functools.lru_cache decorator. lru_cache isn’t hard to use.