Kivy: line continuations

linecont.py

import kivy
kivy.require('1.8.1')

from kivy.app import App
from kivy.lang import Builder

root = Builder.load_string('''
Button:
    text:
        'hello'\\
        'dude'
    on_press:
        self.text = \\
        'bye'
''')

class TestApp(App):
    def build(self):
        return root

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