I wrote a calculator-bot with buttons for Telegram, but when you click on the “=” button, nothing happens, even an error does not come out, what do I not understand?

Question

Python

import telebot
from telebot import types

bot = telebot.TeleBot("1892-----:--------------------mN6dBKNLoWgI5g")

value = ""
old_value = ""

keyboard = telebot.types.InlineKeyboardMarkup()
keyboard.row(   telebot.types.InlineKeyboardButton(" ", callback_data="no"),
                telebot.types.InlineKeyboardButton("C", callback_data="C"),
                telebot.types.InlineKeyboardButton("<=", callback_data="<="),
                telebot.types.InlineKeyboardButton("/", callback_data="/") )

keyboard.row(   telebot.types.InlineKeyboardButton("7", callback_data="7"),
                telebot.types.InlineKeyboardButton("8", callback_data="8"),
                telebot.types.InlineKeyboardButton("9", callback_data="9"),
                telebot.types.InlineKeyboardButton("*", callback_data="*") )

keyboard.row(   telebot.types.InlineKeyboardButton("4", callback_data="4"),
                telebot.types.InlineKeyboardButton("5", callback_data="5"),
                telebot.types.InlineKeyboardButton("6", callback_data="6"),
                telebot.types.InlineKeyboardButton("-", callback_data="-") )

keyboard.row(   telebot.types.InlineKeyboardButton("1", callback_data="1"),
                telebot.types.InlineKeyboardButton("2", callback_data="2"),
                telebot.types.InlineKeyboardButton("3", callback_data="3"),
                telebot.types.InlineKeyboardButton("+", callback_data="+") )

keyboard.row(   telebot.types.InlineKeyboardButton(" ", callback_data="no"),
                telebot.types.InlineKeyboardButton("0", callback_data="0"),
                telebot.types.InlineKeyboardButton(",", callback_data="."),
                telebot.types.InlineKeyboardButton("=", callback_data="=") )

@bot.message_handler(commands = ["start", "calculater"] )
def getmessage(message):
    global value
    if value == "":
        bot.send_message(message.from_user.id, "0", reply_markup=keyboard)
    else:
        bot.send_message(message.from_user.id, value, reply_markup=keyboard)

@bot.callback_query_handler(func=lambda call: True)
def callback_func(query):
    global value, old_value
    data = query.data

    if data == "no" :
        pass
    elif data == "C" :
        value = ""
    elif data == "=" :
        try:
            value == str(eval(value))
        except:
            value = "Ошибка!"
    else:
        value += data

    if value != old_value:
        if value == "":
            bot.edit_message_text(chat_id=query.message.chat.id, message_id=query.message.message_id, text="0", reply_markup=keyboard)
        else:
            bot.edit_message_text(chat_id=query.message.chat.id, message_id=query.message.message_id, text=value, reply_markup=keyboard)

    old_value = value
    if value == "Ошибка!": value = ""

bot.polling(none_stop=False, interval=0)

Answer 1

elif data == "=" :
        try:
            value ==  <---   str(eval(value))
        except:
            value = "Ошибка!"

Answer 2

elif data == "=" :
        try:
            value = str(eval(value))
        except:
            value = "Ошибка!"

Should be =, not ==