If your function gets a restricted range of arguments (say, only the integers 1 through 100), you probably don’t have to worry about the cache growing too large.

Python lets you set default values for function arguments, which is super convenient. But when those default values are mutable (like lists or dictionaries), you're walking into a sneaky bug trap.

Python Functions: Python Functions, Function Argument, Python Recursion Anonymous Function, Global, Local and Nonlocal, Python Global Keyword, Python Modules, Python Package.