Things we should drop in v14. The list is probably not complete. This includes everything deprecated in v12.x and v13.x.

• DRop support for py3.6 - reaches EOL in december anyway …Remove__dict__ from__slots__ #2619 &Update python version in Readme andsetup.py #2636

• Don't know why we skipped that inUse @abstractmethod instead of rasing NotImplementedError #1905, but as BasePersistence is an interface, it makes sense for all methods to be abcs. As flush currently doesn't raise NotImplementedError, this is strictly speaking breaking, so putting this on the v14 milestone.Make basepersistence methods abstractmethod #2624
• non-context based callbacks (i.e. all thepass_* arguments)Dropping non context #2617
• allow_edited argument of CommandHandlerDropping non context #2617
• non-filter arguments of MessageHandlerDropping non context #2617
• RegexHandlerDropping non context #2617
• bot argument ofJobQueueDoc fixes #2597
• use_context argument ofDispatcher andUpdater (this is discussable. we could keep that until v15 as convenience for everyone who already switched to context based callbacks - then again, for adjusting your code to v14, this will be the easiest part …)Dropping non context #2617
• MessageQueue &DelayQueue as a whole (we might want to add some of the logic back inRefactor MessageQueue #2139 after the asyncio switch, but maybe it's cleaner to just remove everything in caseRefactor MessageQueue #2139 will make it only to v14.1 or so)Remove deprecated things #2644
• drop__dict__ from__slots__ (users won't be able to set custom attributes on PTB objects)Remove__dict__ from__slots__ #2619
• makeBP.refresh_*_data abstract methodsMake basepersistence methods abstractmethod #2624
• makePersistence.store_callback_data default toTrue and makeBP.get/update_callback_data abstract methods.Make basepersistence methods abstractmethod #2624
• MoveTelegramDecryptionError toerror.py (851f0b7, it was reverted since it was breaking)move telegramdecryptionerror to error.py #2621

Originally from#2347:

• The@run_async decoratorRemove deprecated things #2644
• Filters.{private, group}Remove deprecated things #2644
• utils.{promise, webhookhandler}Remove deprecated things #2644
• clean argument ofUpdater.start_{polling, webhook}Remove deprecated things #2644
• Think about removingDefaults fromtg.Bot completey and moving them totg.ext.ExtBot. We may have to think about how to handle signatures withDefaultVaule, then, i.e. if_insert_defaults should stay intg.Bot or should be moved totg.ext.ExtBot.Move defaults to ext #2648

• Args & attributes ofChatMemberFix method signatures and expandtest_official #2643
• Bot.{kick_chat_member, get_chat_members_count}Remove deprecated things #2644
• Chat.{kick_member, get_members_count}Remove deprecated things #2644
• ChatAction.{RECORD, UPLOAD}_AUDIO ?Remove deprecated things #2644