Как сделать random на Kivy, для Label, при нажатии на кнопку

Делаю программу, "Правда или действие", и столкнулся с такой проблемой. У меня не работает random, выбивает NameError: name 'random' is not defined, (извините если не правильно написал ошибку). Если что, Пишу на Kivy, в python вместе с Builder.

Вот код:

from kivy.app import App

from kivy.config import Config

from kivy.lang import Builder

from kivy.uix.screenmanager import ScreenManager, Screen

from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label
from kivy.uix.anchorlayout import AnchorLayout

import random

Config.set("graphics", "resizable", "0")
Config.set("graphics", "width", "500")
Config.set("graphics", "height", "850")

category6 = [("Пригни 10 раз"), ("Закрой глаза")]
ListCategory6 = len(category6)

Builder.load_string("""
<MenuScreen>:
    BoxLayout:
        orientation:
            "vertical"
        spacing: 10
        padding: [30]
        Button:
            text: "Начать игру'
            background_color: [5, 1.7, 1, 5]
            size_hint: [1, 0.1]
            font_size: 50
            on_press: root.manager.current = 'settings'

<SettingsScreen>:
    BoxLayout:
        orientation:
            "vertical"
        spacing: 10
        padding: [30]
        Button:
            text: 'Назад'
            size_hint: [1, 0.6]
            background_color: [5, 1, 1, 5]
            on_press: root.manager.current = "menu"
        Label:
            text: "Выбери возрастную категорию"
            size_hint: [1, 0.5]
            font_size: 35
        Button:
            text: "6+"
            background_color: [2.3, 0.1, 4, 1]
            font_size: 40
            on_press: root.manager.current = "Six"

<SixScreen>:
    AnchorLayout:
        anchor_x: "center"
        anchor_y: "top"
        padding: [25]
        Button:
            text: "Назад"
            background_color: [5, 1, 1, 5]
            size_hint: [1, 0.07]
            on_press: root.manager.current = 'settings'
    AnchorLayout:
        anchor_x: "center"
        anchor_y: "bottom"
        padding: [25]
        Button:
            text: "Получить Задание"
            background_color: [0, 1.7, 0, 1]
            size_hint: [1, 0.07]
            on_press: root.manager.current = 'SixLabel'
        Label:
            text: "Задания 6+"
            font_size: 50

<SixLabel>:
    AnchorLayout:
        anchor_x:
            "center"
        anchor_y:
            "top"
        padding: [25]
        Button:
            text: "Назад"
            size_hint: [1, 0.07]
            background_color: [5, 1, 1, 5]
            on_press: root.manager.current = "Six"
        Label:
            text: random.randrange(0, ListCategory6)            
""")

class MenuScreen(Screen):
    pass

class SettingsScreen(Screen):
    pass

class SixScreen(Screen):
    pass

class SixLabel(Screen):
    pass

class randsix(Screen):
    pass

game = ScreenManager()
game.add_widget(MenuScreen(name = 'menu'))
game.add_widget(SettingsScreen(name = 'settings'))

game.add_widget(SixScreen(name = "Six"))

game.add_widget(SixLabel(name = "SixLabel"))

class PlayPutannyApp(App):
    def build(self):

        return game

if __name__ == "__main__":
    PlayPutannyApp().run()