Filters

A filter is a callable (client, event) -> bool. If it returns true, the handler runs. Build one with filters.create.

from pytdbot import Client, types, filters

private = filters.create(lambda _, m: m.chat_id > 0)

@client.on_message(filters=private)
async def only_private(c: Client, message: types.Message):
    await message.reply_text("private chat")

Factory:

@filters.create
async def photos(_, event) -> bool:
    return isinstance(event.content, types.MessagePhoto)

Use the same object as a decorator on plugin handlers (@photos instead of filters=), or pass filters=photos.

See MessagePhoto and Handlers.