The output is different now. 

I update the script for python 3:

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import _thread as thread
import time

def start():
	print("Secondary thread ID:", thread.get_ident())
	import threading

print("Main thread ID:", thread.get_ident())
thread.start_new_thread(start, ())
time.sleep(1)

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and the output is:

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Main thread ID: 4432801280
Secondary thread ID: 123145384259584
Exception ignored in: <module 'threading' from '/Users/iritkatriel/src/cpython-perf/Lib/threading.py'>
Traceback (most recent call last):
  File "/Users/iritkatriel/src/cpython-perf/Lib/threading.py", line 1512, in _shutdown
    assert tlock.locked()
    ^^^^^^^^^^^^^^^^^^^^^
AssertionError: 

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