Let's take the following setup:

languages = CustomLanguage() languages.text = "text" languages.try_again = "again" languages.wrong_user = "wrong" languages.too_short = "short" languages.your_code = "code"

'try_again' is actually not shown when it should. You keep seeing 'text' on both a wrong attempt and a manual user refresh.

'your_code' is also not shown when it should. You always see the default "Your Code:", and 'your_code' does show up but only on a wrong attempt or a manual user refresh (it is not visible on the initial captcha). However, "Your Code:" is still visible up to this point, so you actually see two lines, one time the default one, and one time the new custom one.

If an individual fails to solve the captcha and if another attempt is allowed, the captcha will refresh but it will override variables such as timeout, digits_only and add_noice. This feels like an inconsistency in the logic as a refresh should give a new captcha but with all the user declared variables and values. If the function is declared to not add_noice or to be digits_only, a refresh should not change this behaviour, unless declared otherwise.

To fix this inconsistency the captcha refresh should either follow the user declared variables and values, or one should be able to allow this override to happen or not.

There seems to be an error where there is no timeout event anymore when a user made a wrong attempt, it also seems to not work anymore when a user manually refreshed the CAPTCHA. It still happens though when a user is still on the initial CAPTCHA. I tried this with the default timeout of 90, and a custom timeout. Note that max_incorrect_to_auto_reload has been set to 1, so a timeout should still happen.

Currently the only way to change the digits and hex-digits used in the captcha is to change variables inside of the module. The suggestion would be to be able to declare which digits or letters can be used, but still in a set of 10 (the 2 by 5 input markup grid), or a set of 16 (the 4x4 input markup grid).

The main reason for this suggestion is that some fonts do have characters that could potentially look to similar. For example: 8 and B, or 1 and 7. Be able to declare a custom set of 10 or 16 characters, the captchas could become more user friendly but still bot proof.

Currently the length of the captcha showed is defaulted and hardcoded to be 8 characters long. The suggestion would be to be able to declare the length of the captcha, so that it can display less or even more characters that need to be solved.

Seems like the KeyZenD CAPTCHA can't be found anymore: https://tyt.xyeta.ml/captcha.png

This page returns an 404, and the CAPTCHA can't be found. Maybe it would be smart to add some sort of fallback that turns the option back to 'default' as currently this would break the entire thing?

After some more stress testing it seems to be the case that if someone invites or adds more than 1 user (the option to mass invite your contacts to a channel for example) to the channel where the bot is active, it will only create 1 captcha. Only one user has to complete the captcha, the other users are already 'in' (so to speak).

I try init a new bot with

from telebot import TeleBot
from pyTelegramBotCAPTCHA import CaptchaManager
                                                                    
bot = TeleBot("MY_TOKEN")
captcha_manager = CaptchaManager(bot.get_me().id)

# Message handler for new chat members
@bot.message_handler(content_types=["new_chat_members"])
def new_member(message):
  for new_user in message.new_chat_members:
    captcha_manager.restrict_chat_member(bot, message.chat.id, new_user.id)
    captcha_manager.send_new_captcha(bot, message.chat, new_user)
                                                                    
# Callback query handler
@bot.callback_query_handler(func=lambda callback:True)
def on_callback(callback):
  captcha_manager.update_captcha(bot, callback)
                                                                    
# Handler for correct solved CAPTCHAs
@captcha_manager.on_captcha_correct
def on_correct(captcha):
  bot.send_message(captcha.chat.id, "Congrats! You solved the CAPTCHA!")
  captcha_manager.unrestrict_chat_member(bot, captcha.chat.id, captcha.user.id)
  captcha_manager.delete_captcha(bot, captcha)

# Handler for wrong solved CAPTCHAs
@captcha_manager.on_captcha_not_correct
def on_not_correct(captcha):
  if (captcha.incorrect_digits == 1 and captcha.previous_tries < 2):
    captcha_manager.refresh_captcha(bot, captcha)
  else:
    bot.kick_chat_member(captcha.chat.id, captcha.user.id)
    bot.send_message(captcha.chat.id, f"{captcha.user.first_name} failed solving the CAPTCHA and was banned!")
    captcha_manager.delete_captcha(bot, captcha)

# Handler for timed out CAPTCHAS
@captcha_manager.on_captcha_timeout
def on_timeout(captcha):
  bot.kick_chat_member(captcha.chat.id, captcha.user.id)
  bot.send_message(captcha.chat.id, f"{captcha.user.first_name} did not solve the CAPTCHA and was banned!")
  captcha_manager.delete_captcha(bot, captcha)
  
bot.polling()

And i take a error:

Traceback (most recent call last):
  File "/Users/olivmath/repo/lunes/bot-telegram-cruzeiro/olivmath.py", line 43, in <module>
    bot.polling()
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/telebot/__init__.py", line 660, in polling
    self.__threaded_polling(non_stop, interval, timeout, long_polling_timeout, allowed_updates)
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/telebot/__init__.py", line 722, in __threaded_polling
    raise e
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/telebot/__init__.py", line 682, in __threaded_polling
    self.worker_pool.raise_exceptions()
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/telebot/util.py", line 135, in raise_exceptions
    raise self.exception_info
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/telebot/util.py", line 87, in run
    task(*args, **kwargs)
  File "/Users/olivmath/repo/lunes/bot-telegram-cruzeiro/olivmath.py", line 12, in new_member
    captcha_manager.send_new_captcha(bot, message.chat, new_user)
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/pyTelegramBotCAPTCHA/telebot_captcha.py", line 553, in send_new_captcha
    captcha = Captcha(bot, chat, user, options)
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/pyTelegramBotCAPTCHA/telebot_captcha.py", line 345, in __init__
    self.correct_code, self.image = _random_codeimage(self.options)
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/pyTelegramBotCAPTCHA/telebot_captcha.py", line 865, in _random_codeimage
    image = image.generate_image(code)
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/captcha/image.py", line 228, in generate_image
    im = self.create_captcha_image(chars, color, background)
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/captcha/image.py", line 212, in create_captcha_image
    mask = im.convert('L').point(table)
  File "/Users/olivmath/Library/Caches/pypoetry/virtualenvs/bot-telegram-cruzeiro-rcJnbm2r-py3.10/lib/python3.10/site-packages/PIL/Image.py", line 1680, in point
    return self._new(self.im.point(lut, mode))
TypeError: 'float' object cannot be interpreted as an integer

Hi there,

Great work - loving your captcha bot! I had one idea that would be great to implement. A Refresh button in case the captcha is really hard / barley readable.

Keep it up!

For example, trying initialize the captcha using captcha_manager.send_random_captcha(bot, message.chat, new_user, timeout=60, code_length=4, language="en") will result in TypeError: send_random_captcha() got an unexpected keyword argument 'code_length'

However, following the documentation this should be possible.

While interacting with a captcha button (update_captcha), it should first be checked if that captcha session is still 'available' or not. It not being 'available' can be due to that the captcha message was not deleted properly after kicking a user and that user did not solve it, or that the file that holds that captcha session is somehow removed.

Right now it will throw a KeyError if the session can't be found, but if we can check if that captcha session is not available anymore, we could just remove the captcha instead (whoever presses it) and clean up.