title: Partial read from "stdout" on Python using Popen
body: <p>i'm trying to build a python script, which opens a subprocess (bash script) and reads "stdout" into a variable during 10 seconds. After 10 sec i need to transfer data to server via POST request.
  How to make POST request i know, but how to collect "stdout" during 10 seconds?</p>
  
  <p>i find a lot of examples how to use "Popen", launch bash script and read stderr instantly without biffering, but how to collect output during some time and release is partially?</p>