PrefixHandler

class telegram.ext.PrefixHandler(prefix, command, callback, filters=None, block=True)

Bases: telegram.ext.BaseHandler

Handler class to handle custom prefix commands.

This is an intermediate handler between MessageHandler and CommandHandler. It supports configurable commands with the same options as CommandHandler. It will respond to every combination of prefix and command. It will add a list to the CallbackContext named CallbackContext.args, containing a list of strings, which is the text following the command split on single or consecutive whitespace characters.

Examples

Single prefix and command:

PrefixHandler("!", "test", callback)  # will respond to '!test'.

Multiple prefixes, single command:

PrefixHandler(["!", "#"], "test", callback)  # will respond to '!test' and '#test'.

Multiple prefixes and commands:

PrefixHandler(
    ["!", "#"], ["test", "help"], callback
)  # will respond to '!test', '#test', '!help' and '#help'.

By default, the handler listens to messages as well as edited messages. To change this behavior use ~filters.UpdateType.EDITED_MESSAGE

Note

• PrefixHandler does not handle (edited) channel posts.

Warning

When setting block to False, you cannot rely on adding custom attributes to telegram.ext.CallbackContext. See its docs for more info.

Available In

telegram.ext.Application.handlers

Changed in version 20.0:

• PrefixHandler is no longer a subclass of CommandHandler.

• Removed the attributes command and prefix. Instead, the new commands contains all commands that this handler listens to as a frozenset, which includes the prefixes.

• Updating the prefixes and commands this handler listens to is no longer possible.

Parameters:

• prefix (str | Collection[str]) – The prefix(es) that will precede command.

• command (str | Collection[str]) – The command or list of commands this handler should listen for. Case-insensitive.

• callback (coroutine function) –

  The callback function for this handler. Will be called when check_update() has determined that an update should be processed by this handler. Callback signature:

  async def callback(update: Update, context: CallbackContext)
  

  The return value of the callback is usually ignored except for the special case of telegram.ext.ConversationHandler.

• filters (telegram.ext.filters.BaseFilter, optional) – A filter inheriting from telegram.ext.filters.BaseFilter. Standard filters can be found in telegram.ext.filters. Filters can be combined using bitwise operators (& for and, | for or, ~ for not)

• block (bool, optional) –

  Determines whether the return value of the callback should be awaited before processing the next handler in telegram.ext.Application.process_update(). Defaults to True.

  See also

  Concurrency

commands

The commands that this handler will listen for, i.e. the combinations of prefix and command.

Type:

FrozenSet[str]

callback

The callback function for this handler.

Type:

coroutine function

filters

Optional. Only allow updates with these Filters.

Type:

telegram.ext.filters.BaseFilter

block

Determines whether the return value of the callback should be awaited before processing the next handler in telegram.ext.Application.process_update().

Type:

bool

check_update(update)

Determines whether an update should be passed to this handler’s callback.

Parameters:

update (telegram.Update | object) – Incoming update.

Returns:

The list of args for the handler.

Return type:

list

collect_additional_context(context, update, application, check_result)

Add text after the command to CallbackContext.args as list, split on single whitespaces and add output of data filters to CallbackContext as well.