#!/usr/bin/env python3
# From https://stackoverflow.com/a/25755038
from subprocess import Popen, PIPE, STDOUT
from os import remove

shell = Popen(['dd', 'if=/dev/zero', 'of=/dev/null', 'status=progress'],
              stdout=PIPE, stderr=STDOUT, universal_newlines=True, bufsize=1)

remove('output')
try:
    for line in iter(shell.stdout.readline, b''):
        f = open('output', 'w')
        if (line.strip() != ''):  # Ignore empty lines (always 1 at the start)
            line = line.rstrip()
            print(line)
            f.write(line)
        f.close()

except KeyboardInterrupt:
    f.close()
    exit()