Python: live output from subprocess command

file.py

# From http://stackoverflow.com/a/18422264

import subprocess
import sys

with open('test.log', 'w') as f:
    process = subprocess.Popen(your_command, stdout=subprocess.PIPE)
    for line in iter(process.stdout.readline, ''):  # With Python 3, you need iter(process.stdout.readline, b'') (i.e. the sentinel passed to iter needs to be a binary string, since b'' != '')
        sys.stdout.write(line)
        f.write(line)

The above does not work on Python 3
for line in iter(process .stdout.readline):
 TypeError: 'builtin_function_or_method' object is not iterable