Here's what I expect to happen (Python2 behavior):


Python 2.7.14+ (default, Dec  5 2017, 15:17:02)
[GCC 7.2.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from dummy_threading import Thread
>>> def f(): print 'foo'
...
>>> t = Thread(target=f)
>>> t.start()
foo
>>> t.is_alive()
False
>>>




Here's what actually happens (Python3.6):


Python 3.6.4 (default, Jan  5 2018, 02:13:53)
[GCC 7.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from dummy_threading import Thread
>>> def f(): print('foo')
...
>>> t = Thread(target=f)
>>> t.start()
foo
>>> t.is_alive()
True
>>>



After completion of the target function, I would expect .is_alive() to return False for an instance of dummy_thread.Thread. Instead, it returns True until the .join() method of the instance of dummy_thread.Thread is called.