@bot.callback_query_handler(func=lambda call: call.data.split('_')[0] == 'category')
def show_product(call)
        ....
        some code
        ....
        bot.send_photo(call.message.chat.id, product.img.read(), caption=f'Вы вибрали продукт {product.title}\n\n'
                                                                         f'Описание: \n'
                                                                         f'{product.description} \n\n'
                                                                         f'Цена: <b>{product.price}</b>',
                                                                         reply_markup=keyboard,
                                                                         parse_mode='HTML')

@bot.callback_query_handler(func=lambda call: call.data.split('_')[0] == 'back')
def go_back(call):

    try:
        ...
        some awesome code
        ...

        bot.edit_message_text(...)

    expect teleport.apihelper.ApiExeption:

        bot.delete_message(...)

@bot.callback_query_handler(func=lambda call: call.data.split('_')[0] == 'back')
def buy_product(call):

    ...
    some useful code
    ...

    db.Cart.objects(user=user).add_product(product)