# --↓のコードを追加する--
import os
import sys

f = open(os.devnull, 'w')
sys.stderr = f
sys.stdout = f
sys.stdin = f
# ------------------------

from kivy.app import App
from kivy.uix.label import Label


class MyApp(App):
    def build(self):
        return Label(text="Hello world")


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