Why is the output of (x.transfer_ru()) and (x.lengwich_selection) different and how to fix it?

Question

Python

import requests, bs4
letters_ru = ("б", "п", "в", "ф", "д", "т", "з", "с", "ж", "ш", "ч", "ц", "щ", "г", "к", "х", "м", "н", "л", "р")

class Translate():

    def __init__(self):
        self.word = input("Введите слово:")
        self.word = self.word.lower()
        self.link = "https://wooordhunt.ru/word/" + self.word
        self.link = requests.get(self.link)
        self.link = bs4.BeautifulSoup(self.link.text, "html.parser")

    def lengwich_selection(self): #Определение языка на котором написано слово
        self.word_list = list(self.word)
        if letters_ru in self.word_list:
            return self.transfer_ru()

    def transfer_eng(self): #Перевод с английского на русский
        self.translate_link = self.link.select(".t_inline_en")
        self.translate = self.translate_link[0].getText()
        return ("Перевод слова - ") + self.translate.strip()

    def transfer_ru(self): #Перевод с русского языка
        self.translate_link = self.link.select(".t_inline")
        self.translate = self.translate_link[0].getText()
        return ("Перевод слова - ") + self.translate.strip()

    def transkription(self): #Транскрипция (в том случае если язык английский)
        self.transkription_word = self.link.select(".transcription")
        self.transkription_amer = self.transkription_word[0].getText()
        self.transkription_brit = self.transkription_word[1].getText()
        return self.transkription_amer.strip(), self.transkription_brit.strip()



x = Translate()
print(x.transfer_ru())
print(x.lengwich_selection())

Output (if the word is in Russian):
Translation of the word - sea, water, waters, blue, waves, flood, deep, tide, drink, briny, pond
None

Answer 1

oh-my-selection returns None if it doesn't find a list of all Russian letters in the list of words . And since words are made up of strings, and no string is a tuple of Russian letters, oh my God, the selection always returns None.