Without functions: by repeatedly writing the code to draw a triangle with. With a Python function call: by generating lots of coordinates and feeding them to your “draw triangle” function.

Working with files in Python is pretty easy. But there’s a common mistake that can sneak into your code. Not closing the file ...

Functions that rely on something outside the function itself (e.g., a network call, or a read from disk) are harder to memoize, though it can still be done.