`enter code here` from threading import Thread
 from queue import Queue, Empty

def readlines(process, queue):
    while process.poll() is None:
        queue.put(process.stdout.readline())

def startProcess(self):
    self.process = subprocess.Popen(['./subtest.sh'],
        stdout=subprocess.PIPE,
        stdin=subprocess.PIPE,
        stderr=subprocess.PIPE)

    self.queue = Queue()
    self.thread = Thread(target=readlines, args=(self.process, self.queue))
    self.thread.start()

    self.after(100, self.updateLines)

def updateLines(self):
    try:
        line = self.queue.get(False) # False for non-blocking, raises Empty if empty
        self.console.config(state=tkinter.NORMAL)
        self.console.insert(tkinter.END, line)
        self.console.config(state=tkinter.DISABLED)
    except Empty:
        pass

    if self.process.poll() is None:
        self.after(100, self.updateLines)