So far we've seen :doc:`how to register a callback function <../start/updates>` that executes every time a specific update comes from the server, but there's much more than that to come.

Here we'll discuss about :class:`~pyrogram.Filters`. Filters enable a fine-grain control over what kind of updates are allowed or not to be passed in your callback functions, based on their inner details.

Let's start right away with a simple example:

• This example will show you how to only handle messages containing an :class:`~pyrogram.Audio` object and ignore any other message. Filters are passed as the first argument of the decorator:

  from pyrogram import Filters
  
  
  @app.on_message(Filters.audio)
  def my_handler(client, message):
      print(message)

• or, without decorators. Here filters are passed as the second argument of the handler constructor; the first is the callback function itself:

  from pyrogram import Filters, MessageHandler
  
  
  def my_handler(client, message):
      print(message)
  
  
  app.add_handler(MessageHandler(my_handler, Filters.audio))

Filters can also be used in a more advanced way by inverting and combining more filters together using bitwise operators ~, & and |:

• Use ~ to invert a filter (behaves like the not operator).
• Use & and | to merge two filters (behave like and, or operators respectively).

Here are some examples:

• Message is a text message and is not edited.

  @app.on_message(Filters.text & ~Filters.edited)
  def my_handler(client, message):
      print(message)

• Message is a sticker and is coming from a channel or a private chat.

  @app.on_message(Filters.sticker & (Filters.channel | Filters.private))
  def my_handler(client, message):
      print(message)

Some filters, like :meth:`~pyrogram.Filters.command` or :meth:`~pyrogram.Filters.regex` can also accept arguments:

• Message is either a /start or /help command.

  @app.on_message(Filters.command(["start", "help"]))
  def my_handler(client, message):
      print(message)

• Message is a text message or a media caption matching the given regex pattern.

  @app.on_message(Filters.regex("pyrogram"))
  def my_handler(client, message):
      print(message)

More handlers using different filters can also live together.

@app.on_message(Filters.command("start"))
def start_command(client, message):
    print("This is the /start command")


@app.on_message(Filters.command("help"))
def help_command(client, message):
    print("This is the /help command")


@app.on_message(Filters.chat("PyrogramChat"))
def from_pyrogramchat(client, message):
    print("New message in @PyrogramChat")