Issue using print statement in a thread

[bweiss1258]

I'm having an issue with text output from a thread staying visible in the interpreter. The code below can be used to demonstrate the problem following these steps.

1. Place the code into a file.
2. Start Python 2.7 and import the file.
3. Execute the startThread() function to start the thread.

At this point you should see "hello world" printed every 3 seconds. The issue is that when any key is pressed the all the "hello world" text disappears. I need to find a way to maintain the text printed by the thread in the interpreter. Any ideas or help is appreciated.

from __future__ import print_function
import threading
import time

class TestThread(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self, name='test')
        self._done = False

    def run(self):
        while not self._done:
            print("hello world")
            time.sleep( 3 )

    def close(self):
        self._done = True

td = None
def startThread( ):
    global td
    print( "Starting thread.")
    td = TestThread( )
    td.setDaemon( True )
    td.start( )