What happened to thread.start_new_thread in python 3

Question

I liked the ability to turn a function into a thread without the unnecessary line to define a class. I know about _thread, however it appears that you are not supposed to use _thread. Is there a good-practice equivalent of thread.start_new_thread for python 3?

Answer 1

threading.Thread(target=some_callable_function).start()

or if you wish to pass arguments,

threading.Thread(target=some_callable_function,
 args=(tuple, of, args),
 kwargs={'dict': 'of', 'keyword': 'args'},
 ).start()

• lemiant: I am using method 2 to pass one argument to a thread, and am getting the error: argument after * must be sequence, not it. Do you know what this means?
• Amber: Make sure you're passing (firstarg,) not (firstarg) - remember that single-element tuples need the trailing comma to be interpreted as a tuple.
• henrikstroem: What would the callable method signature look like? If I use something like callable(**kwargs): I get TypeError: callable() takes 0 positional arguments but 1 was given, and if I use callable(kwargs): I get TypeError: callable() got an unexpected keyword argument 'raw'.
• Smart Manoj: @henrikstroem threading.Thread(target=callable,kwargs=kwargs)

Answer 2

Unfortunately there is not a direct equivalent, because Python 3 is meant to be more portable than Python 2 and the _thread interface is seen as too low-level for this purpose.

In Python 3 the best practice is usually to use threading.Thread(target=f...). This uses different semantics, but is preferred because the interface is easier to port to other Python implementations.