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.

But Cython can also be used to incrementally accelerate Python functions, chiefly ones that perform math. The downside is that Cython uses its own peculiar syntax to work its magic, so porting ...