Kivy- Python -检查textField是否为空

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.textinput import TextInput

class MyBoxLayout(BoxLayout):
    def __init__(self, **kwargs):
        super(MyBoxLayout, self).__init__(**kwargs)
        
        self.orientation = 'vertical'
        
        self.text_input = TextInput(multiline=False)
        self.add_widget(self.text_input)
        
        self.check_button = Button(text='Check', on_press=self.check_text_input)
        self.add_widget(self.check_button)
        
    def check_text_input(self, instance):
        if self.text_input.text.strip() == '':
            print('TextField is empty')
        else:
            print('TextField is not empty')

class MyApp(App):
    def build(self):
        return MyBoxLayout()

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