Running a command infinitely until it succeeds

infinite_cmd.py

import subprocess
import sys 

def run_command(command):
    process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    while True:
        output = process.stdout.read(1).decode()
        if output == '' and process.poll() is not None:
            break
        if output != '':
            sys.stdout.write(output)
            sys.stdout.flush()

    return process.returncode

while True:
    code = run_command(sys.argv[1:])
    if code == 0:
        break
    else:
        print("Retrying as previously failed with %s" % code)