Kivy是Python中与平台无关的GUI工具。由于可以在Android，IOS，Linux和Windows等操作系统上运行，因此Kivy为您提供了编写代码一次并在不同平台上运行的功能。它基本上用于开发Android应用程序，但并不意味着它不能在桌面应用程序上使用。
按钮是带有相关操作的标签，该操作在按下按钮时触发（或在单击/触摸后释放）。我们可以在按钮后面添加功能并设置按钮样式。
# import kivy module
import kivy
# this restrict the kivy version below this kivy version you cannot
# use the app or software
kivy.require("1.9.1")
# base Class of your App inherits from the App class.
# app:always refers to the instance of your application
from kivy.app import App
# creates the button in kivy if not imported shows the error
from kivy.uix.button import Button
# class in which we are creating the button
class ButtonApp(App):
def build(self):
# use a (r, g, b, a) tuple
btn = Button(text ="Push Me !",
font_size ="20sp",
background_color =(1, 1, 1, 1),
color =(1, 1, 1, 1),
size =(32, 32),
size_hint =(.2, .2),
pos =(300, 250))
# bind() use to bind the button to function callback
btn.bind(on_press = self.callback)
return btn
# callback function tells when button pressed
def callback(self, event):
print("button pressed")
print('Kivy!')
# creating the object root for ButtonApp() class
root = ButtonApp()
#run function runs the whole program. run() method which calls the #target function passed to the constructor.
root.run()