import os import subprocess r, w = os.pipe() with subprocess.Popen(['bash', '-c', '''for i in 1 2 3 4 do echo $i >&{} echo "$$: $i" done exit 1'''.format(w)], pass_fds=[w]) as p, open(r) as f: os.close(w) for i in map(str.rstrip, f): print('{}: {}'.format(os.getpid(), i)) print('done: {}'.format(p.returncode))