Does any standard "comes with batteries" method exist to clear the terminal screen from a Python script, or do I have to go curses (the libraries, not the words)?
If all you need is to clear the screen, this is probably good enough. The problem is there's not even a 100% cross platform way of doing this across linux versions. The problem is the implementations of the terminal all support slightly different things. I'm fairly sure that "clear" will work everywhere. But the more "complete" answer is to use the xterm control characters to move the cursor, but that requires xterm in and of itself.
Without knowing more of your problem, your solution seems good enough.
Clear terminal in Python