Description
Steps to Reproduce
- Create a custom filter class inheriting from BaseFilter. In its init method, call super().init()
class MenuFilter(BaseFilter):
def __init__(self, handler_menu_name: str = None, is_admin_only: bool = False):
super().__init__()
self.handler_menu_name = handler_menu_name
self.is_admin_only = is_admin_only
# ... other initialization code ...
# This method is expected to be called, but won't be due to the error
def __call__(self, update, context) -> bool:
# ... filtering logic ...
return True2.Add this custom filter to a MessageHandler using the & (AND) operator, combined with other built-in filters like
filters.Regex or filters.UpdateType.MESSAGE.
import re
from telegram.ext import MessageHandler, filters
compiled_pattern = re.compile(f"^{re.escape(btn_text)}$")
mf = MenuFilter(handler_menu_name=menu_name, is_admin_only=True)
application.add_handler(
MessageHandler(
filters.Regex(compiled_pattern)
& filters.UpdateType.MESSAGE
& mf, # Error occurs here
func,
block=True
)
)3.Run the bot and send a message that would trigger this MessageHandler (e.g., a button text matching btn_text).
Expected behaviour
The init method of the MenuFilter class completes successfully.
The MessageHandler is added without issues.
Upon receiving a message, the call method (or filter method, if inheriting from MessageFilter) of MenuFilter is invoked, and the filtering logic is applied.
Actual behaviour
An AttributeError occurs during the MessageHandler registration:
ERROR | 2025-07-04 03:35:42 | AnkaNestLogger | Handler kurulumunda hata: 'MenuFilter' object has no attribute '_data_filter'
Traceback (most recent call last):
File "C:\\main\main.py", line 418, in setup_handlers
filters.Regex(pattern)
~~~~~~~~~~~~~~~~~~~~~~
& filters.UpdateType.MESSAGE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
& mf,
^~~~
File "C:\Users\asus\AppData\Local\Programs\Python\Python313\Lib\site-packages\telegram\ext\filters.py", line 201, in __and__
return _MergedFilter(self, and_filter=other)
File "C:\Users\asus\AppData\Local\Programs\Python\Python313\Lib\site-packages\telegram\ext\filters.py", line 425, in __init__
and self.and_filter.data_filter
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\asus\AppData\Local\Programs\Python\Python313\Lib\site-packages\telegram\ext\filters.py", line 249, in data_filter
return self._data_filter
^^^^^^^^^^^^^^^^^
AttributeError: 'MenuFilter' object has no attribute '_data_filter'. Did you mean: 'data_filter'?Operating System
Windows 11
Version of Python, python-telegram-bot & dependencies
python-telegram-bot 22.2
Bot API 9.0
Python 3.13.5Relevant log output
ERROR | 2025-07-04 03:35:42 | AnkaNestLogger | Handler kurulumunda hata: 'MenuFilter' object has no attribute '_data_filter'
Traceback (most recent call last):
File "C:\main\main.py", line 418, in setup_handlers
filters.Regex(pattern)
~~~~~~~~~~~~~~~~~~~~~~
& filters.UpdateType.MESSAGE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
& mf,
^~~~
File "C:\Users\asus\AppData\Local\Programs\Python\Python313\Lib\site-packages\telegram\ext\filters.py", line 201, in __and__
return _MergedFilter(self, and_filter=other)
File "C:\Users\asus\AppData\Local\Programs\Python\Python313\Lib\site-packages\telegram\ext\filters.py", line 425, in __init__
and self.and_filter.data_filter
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\asus\AppData\Local\Programs\Python\Python313\Lib\site-packages\telegram\ext\filters.py", line 249, in data_filter
return self._data_filter
^^^^^^^^^^^^^^^^^
AttributeError: 'MenuFilter' object has no attribute '_data_filter'. Did you mean: 'data_filter'?Additional Context
This error stems from the _MergedFilter class's init method in filters.py attempting to access the data_filter attribute of the combined filters.
class _MergedFilter(UpdateFilter):
__slots__ = ("and_filter", "base_filter", "or_filter")
def __init__(
self,
base_filter: BaseFilter,
and_filter: Optional[BaseFilter] = None,
or_filter: Optional[BaseFilter] = None,
):
super().__init__()
self.base_filter = base_filter
if self.base_filter.data_filter:
self.data_filter = True
self.and_filter = and_filter
if (
self.and_filter
and not isinstance(self.and_filter, bool)
and self.and_filter.data_filter #<-- this line leads to error.
):
self.data_filter = True
self.or_filter = or_filter
if self.or_filter and not isinstance(self.and_filter, bool) and self.or_filter.data_filter:
self.data_filter = TrueThere are very few examples of this in the documentation and I spent 1 day trying to solve this problem and they changed it but even the administrators didn't understand it and told me that I had to use type handler.
https://t.me/pythontelegrambotgroup/780976
from telegram.ext.filters import MessageFilter
class FilterAwesome(MessageFilter):
def filter(self, message):
return 'python-telegram-bot is awesome' in message.text
# Remember to initialize the class.
filter_awesome = FilterAwesome()
awesome_handler = MessageHandler(filter_awesome, callback)
application.add_handler(awesome_handler)BaseFilter was acting as if there was no mf line even though it was there
class MenuFilter(BaseFilter):
def __init__(self, handler_menu_name: str = None, is_admin_only: bool = False):
super().__init__(data_filter=False) # Bu satırı ekleyin
self.handler_menu_name = handler_menu_name
self.is_admin_only = is_admin_only
def __call__(self, update, context) -> bool:
# 1) Mutlaka bir chat olmalı
chat = update.effective_chat
if not chat:
return FalseWhile such examples are helpful for cases where MessageFilter's init cor 5667 rectly initializes data_filter, they do not provide a general example for directly inheriting from BaseFilter and handling the data_filter requirement manually. This can lead to confusion for users who choose to inherit directly from BaseFilter or overlook this specific requirement.