gistfile1.txt

import errno
import os
import pty
import select
from subprocess import Popen, STDOUT

master_fd, slave_fd = pty.openpty()  # provide tty to enable
                                     # line-buffering on ruby's side
                                   
proc = Popen(['python', 'test.py'],
             stdin=slave_fd, stdout=slave_fd, stderr=STDOUT, close_fds=True)

os.close(slave_fd)
os.write(master_fd, b'abc\n')
timeout = .04 # seconds
try:
    while 1:
        ready, _, _ = select.select([master_fd], [], [], timeout)
        if ready:
            try:
                data = os.read(master_fd, 512)
            except OSError as e:
                if e.errno != errno.EIO:
                    raise
                break # EIO means EOF on some systems
            else:
                if not data: # EOF
                    break
                print('got ' + repr(data))
                
finally:
    os.close(master_fd)
    if proc.poll() is None:
        proc.kill()
    proc.wait()

print("This is reached!")