main.py

from kivy.app import App
from kivy.uix.button import Button
from kivy.properties import NumericProperty, StringProperty


class OneTimeButton(Button):
    count = 0
    index = NumericProperty()

    def __init__(self):
        super().__init__()
        self.index = OneTimeButton.count
        OneTimeButton.count += 1

    def on_press(self):
        self.disabled = True
        print(self.index)


class GuessingButton(Button):
    hidden_text = StringProperty('')

    def __init__(self, hidden_text):
        super().__init__()
        self.hidden_text = hidden_text

    def on_press(self):
        if self.text == '':
            self.text = self.hidden_text
        else:
            self.text = ''


class DemoApp(App):
    def build(self):
        for i in range(5):
            self.root.add_widget(OneTimeButton())
        for i in range(5):
            self.root.add_widget(GuessingButton(str(i)))


if __name__ == '__main__':
    app = DemoApp()
    app.run()