import _thread
import time
barrier = 0


def method():
    import threading  # Will make threading the wrong thread.
    global barrier
    barrier = 1


_thread.start_new_thread(method, ())

while barrier != 1:
    time.sleep(.1)
    
import threading
print(threading.main_thread())
print(threading.current_thread())

# CPython will give an exception if we exit here without waiting
# for what it thinks is the main thread to exit first .
threading.main_thread().join()