#!/usr/bin/env python3
import subprocess
# change the round factor if you like
r = 1

screens = [l.split() for l in subprocess.check_output(
    ["xrandr"]).decode("utf-8").strip().splitlines() if " connected" in l]

scr_data = []
for s in screens:
    try:
        scr_data.append((
            s[0],
            float(s[-3].replace("mm", "")),
            float(s[-1].replace("mm", ""))
            ))
    except ValueError:
        pass

print(("\t").join(["Screen", "width", "height", "diagonal\n"+32*"-"]))
for s in scr_data:
    scr = s[0]; w = s[1]/25.4; h = s[2]/25.4; d = ((w**2)+(h**2))**(0.5)
    print(("\t").join([scr]+[str(round(n, 1)) for n in [w, h, d]]))