Python Terminal Text Output Formatting

Question

I have a python program that outputs a few numpy matricies and some other information to my terminal in this fashion:

Currently, to view the data, I follow this order:

1. Print data
2. Clear Screen
3. Re print (and repeat)

However, this is really inefficient. What I would like to be able to do is to see the numbers changing as the program runs, but without the overhead of screen clearing. Is there a way I can format my output using native python so that I won't have to to this expensive operation? The idea is I can have something that works like htop (or similar formatted terminal programs, such as cmus).

Answer 1

Why clearing the screen is such an expense? The terminal has, most likely, a buffer of fixed size which is overwritten as older lines "scroll up". Rewriting the output may take a few ms (or more, depends on how big it is). If the output is really massive, consider a different approach, e.g. slice your matrices and only output what changed or use a plot to inspect your data (hint: matrices can be displayed as images). If you really need a "fixed" display on a terminal, then curses module is the way to go, but then your output cannot be that big, otherwise it would not fit a terminal window anyway. If you need to implement scrolling, then consider moving to a graphical user interface.

Answer 2

you can use watch shell command

if it is a python script or can be trasformed in an unique python script

watch -n 1 'python xxx.py'

1 is the refresh time

-d highlight changes between updates