Wante to change the current context to my custom one.

[taaaal]

I made a custom command decorator so that it would apply to all of my commands via typing but it doesn't seem to have been so successful. I would appreciate it if someone would help me to set it up in the bot settings.

class BetterContext(CallbackContext):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        
   async def send(self, ...):
       ...

def command(name):
    def decorator(func):
        async def wrapper(_, update: Update, context: BetterContext):
            await func(_, update, context)
        wrapper.is_command = True
        return wrapper 
    return decorator

@command(name='demo')
async def demo_cmd(self, update: Update, context: BetterContext): # This command is part of a class
    await context.send(text='test')                               # so, the self is necessary :D

Traceback (most recent call last):
 File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\telegram\ext\_application.py", line 1195, in process_update
   await coroutine
 File "C:\Users\User\AppData\Local\Programs\Python\Python39\lib\site-packages\telegram\ext\_basehandler.py", line 153, in handle_update
   return await self.callback(update, context)
 File "C:\Users\User\source\repos\bot\utils.py", line 123, in wrapper
   await func(self, update, context)
 File "C:\Users\User\source\repos\bot\bot.py", line 50, in demo_cmd
   await context.send(text='test')
AttributeError: 'CallbackContext' object has no attribute 'send'
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⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ^

[Bibo-Joshi]

Type hinting doesn't change the type of the argument that you pass. Please have a look at https://docs.python-telegram-bot.org/en/v20.6/telegram.ext.contexttypes.html and https://docs.python-telegram-bot.org/en/v20.6/examples.html#examples-contexttypesbot for info on how to make PTB use your sublass.

[taaaal]

Well, I see. thanks!
By the way, it goes the same way if I want to customize the Update by my own?

[Bibo-Joshi]

No. PTB does not provide any ready made way to customize that class - as the contents of the Update class are defined by Telegram, there way way fewer use cases for that than for customizing the CallbackContext class.
If you use run_polling, you'll have to override Bot.get_updates and then use ApplicationBuilder.bot() to you a custom bot instance.
For run_webhook, there is currently no way to achieve this without digging into the (private) internals of PTB. You would have to use a custom webhook setup and use YourUpdateClass.de_json instead of Update.de_json.

[taaaal]

I see, I have asked this because I want to get from the CallbackContext object (my BetterContext object) those effective_user, effective_message, and effective_chat attributes. But, I have no access to them from the context object. I have tried to find CallableContext's methods that would transfer this data for me, but I haven't found it so far. Tried this trick as-well, but no succession,

def command(name):
    def decorator(func):
        async def wrapper(self, update: Update, context: BetterContext):
            await func(self, update, context)
            for attr in ('effective_chat', 'effective_user', 'effective_message'):
                value = getattr(update, attr)
                setattr(context, attr, value)
        wrapper.is_command = True
        return wrapper 
    return decorator

[Bibo-Joshi]

PTB makes a clear distinction between the update argument and the context argument to emphasize which information orginates from Telegram (the update) and what is PTB-specific infrastructure (context). the effective_* attributes are pure shortcuts to information within the update argument and are hence located in the Update class. I see no added benefit in having them available in context as well.

In any case, one way to make that work is to extract these values from update in BetterContext.from_update (which would override CallbackContext.from_update, as shocased in the examples linked above).