def init_class_select_panel(instance):
    instance.__setattr__("set_class0_btn_callback", lambda: instance.current_class_number.set(0))
    instance.__setattr__("set_class1_btn_callback", lambda: instance.current_class_number.set(1))
    instance.__setattr__("set_class2_btn_callback", lambda: instance.current_class_number.set(2))
    instance.__setattr__("set_class3_btn_callback", lambda: instance.current_class_number.set(3))
    instance.__setattr__("set_class4_btn_callback", lambda: instance.current_class_number.set(4))
    instance.__setattr__("set_class5_btn_callback", lambda: instance.current_class_number.set(5))
    instance.__setattr__("set_class6_btn_callback", lambda: instance.current_class_number.set(6))
    instance.__setattr__("set_class7_btn_callback", lambda: instance.current_class_number.set(7))
    instance.__setattr__("set_class8_btn_callback", lambda: instance.current_class_number.set(8))
    instance.__setattr__("set_class9_btn_callback", lambda: instance.current_class_number.set(9))
    instance.__setattr__("set_class10_btn_callback", lambda: instance.current_class_number.set(10))
    instance.__setattr__("set_class11_btn_callback", lambda: instance.current_class_number.set(11))
    instance.__setattr__("set_class12_btn_callback", lambda: instance.current_class_number.set(12))
    instance.__setattr__("set_class13_btn_callback", lambda: instance.current_class_number.set(13))
    instance.__setattr__("set_class14_btn_callback", lambda: instance.current_class_number.set(14))
    instance.__setattr__("set_class15_btn_callback", lambda: instance.current_class_number.set(15))
    instance.__setattr__("set_class16_btn_callback", lambda: instance.current_class_number.set(16))
    instance.__setattr__("set_class17_btn_callback", lambda: instance.current_class_number.set(17))
    instance.__setattr__("set_class18_btn_callback", lambda: instance.current_class_number.set(18))
    instance.__setattr__("set_class19_btn_callback", lambda: instance.current_class_number.set(19))
