bpo-43723: deprecate camelCase aliases from threading

[JelleZijlstra]

The snake_case names have existed since Python 2.6, so there is
no reason to keep the old camelCase names around. One similar
method, threading.Thread.isAlive, was already removed in
Python 3.9 (bpo-37804).

https://bugs.python.org/issue43723

[vstinner]

Suggested change

	The following `threading` methods are now deprecated and should be replaced:
	`threading.currentThread` => :func:`threading.current_thread`;
	`threading.activeCount` => :func:`threading.active_count`;
	`threading.Condition.notifyAll` => :meth:`threading.Condition.notify_all`;
	`threading.Event.isSet` => :meth:`threading.Event.is_set`;
	`threading.Thread.setName` => :attr:`threading.Thread.name`;
	`threading.thread.getName` => :attr:`threading.Thread.name`;
	`threading.Thread.isDaemon` => :attr:`threading.Thread.daemon`;
	`threading.Thread.setDaemon` => :attr:`threading.Thread.daemon`.
	Patch by Jelle Zijlstra.
	The following `threading` methods are now deprecated and should be replaced:
	* `threading.currentThread` => :func:`threading.current_thread`;
	* `threading.activeCount` => :func:`threading.active_count`;
	* `threading.Condition.notifyAll` => :meth:`threading.Condition.notify_all`;
	* `threading.Event.isSet` => :meth:`threading.Event.is_set`;
	* `threading.Thread.setName` => :attr:`threading.Thread.name`;
	* `threading.thread.getName` => :attr:`threading.Thread.name`;
	* `threading.Thread.isDaemon` => :attr:`threading.Thread.daemon`;
	* `threading.Thread.setDaemon` => :attr:`threading.Thread.daemon`.
	Patch by Jelle Zijlstra.

[JelleZijlstra]

I had to do it a little differently to get the markup working and work around python/core-workflow#394.

[vstinner]

I had to do it a little differently to get the markup working and work around python/core-workflow#394.

If you put each item on a long line, you should not be affected by https://github.com/python/core-workflow/issues/394 no?

[JelleZijlstra]

blurb reflows the lines to make them fit into 76 characters, so I have to make each line fit into 76 characters to avoid the bug.

[vstinner]

It doesn't work without these empty lines?

[JelleZijlstra]

That's right, they all get mushed together into a single line

[vstinner]

I would prefer to say "deprecated" somewhere, rather than "still supported".

[JelleZijlstra]

Reworded

[vstinner]

Thank you @JelleZijlstra for all updates. The final merged change provides very good explanation on the rationale and also great guidance to fix affected. It's really important to provide good guidance on deprecations, to make developers' life easier.

[terryjreedy]

That should have been 'backport', not 'revert' in the titles above. Fixed for 3.8 backport. Sorry for any confusion.

[vstinner]

Thanks for backports @terryjreedy ;-)