utils.py

import cv2
import re
import pytesseract
import telegram
from telegram.ext import Handler

pytesseract.pytesseract.tesseract_cmd = 'C:/Program Files/Tesseract-OCR/tesseract.exe'

class WebError(Exception):
    pass

class Offline(Exception):
    pass

class AdminHandler(Handler):
    def __init__(self, admin_ids):
        super().__init__(self.cb)
        self.admin_ids = admin_ids

    def cb(self, update: telegram.Update, context):
        update.message.reply_text('Unauthorized access!')

    def check_update(self, update: telegram.update.Update):
        if update.message is None or update.message.from_user.id not in self.admin_ids:
            return True

        return False

def break_captcha():
        img = cv2.imread('captcha.png')
        image = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
        se = cv2.getStructuringElement(cv2.MORPH_RECT, (8,8))
        bg = cv2.morphologyEx(image, cv2.MORPH_DILATE, se)
        out_gray = cv2.divide(image, bg, scale=255)
        out_binary = cv2.threshold(out_gray, 0, 255, cv2.THRESH_OTSU )[1]
    
        captcha = pytesseract.image_to_string(out_binary, config='--psm 13 -c tessedit_char_whitelist=ABCDEFGHIJKLMNPQRSTUVWYZ')
        denoised_captcha =  re.sub('[\W_]+', '', captcha).strip()
        
        return denoised_captcha