title: How to execute bunch of commands in one pipe using python?
body: <p>I have issue about executing commands in python.
  Problem is:
  In our company we have bought commercial software that can be used either GUI or Command line interface. I have been assigned a task that automize it as possible as. First I thought about using CLI instead of GUI. But then i have encountered a problem about executing multiple commands.
  Now, I want to execute CLI version of that soft with arguments and continue executing commands in its menu(I dont mean execute script with args again.I want , once initial commands executed , it will open menu and i want to execute soft's commands inside Soft's menu at background). Then redirect output to variable. 
  I know, I must use subprocess with PIPE , but I didn't manage it.</p>
  
  <pre><code>import subprocess
  proc=subprocess.Popen('./Goldbackup -s -I -U', shell=True, stdout=subprocess.PIPE)
  output=proc.communicate()[0]
  proc_2 = subprocess.Popen('yes\r\n/dir/blabla/\r\nyes', shell=True, stdout=subprocess.PIPE) 
  # This one i want to execute inside first subprocess
  </code></pre>