Python Kivy Framework
Kivy is an open source Python library for rapid development of applications that make use of innovative user interfaces, such as multi-touch apps. It runs on Linux, Windows, OS X, Android, iOS, and Raspberry Pi.
Installation
pip install kivyBasic Application
To create a Kivy app, you subclass the App class and implement the build() method, returning a widget tree.
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()Layouts
Kivy uses layouts to arrange widgets. BoxLayout is one of the most common.
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
class MenuApp(App):
def build(self):
layout = BoxLayout(orientation='vertical')
btn1 = Button(text='Start Game')
btn2 = Button(text='Settings')
btn3 = Button(text='Exit')
layout.add_widget(btn1)
layout.add_widget(btn2)
layout.add_widget(btn3)
return layout
if __name__ == '__main__':
MenuApp().run()Handling Events
You can bind callbacks to events like on_press.
def on_button_press(instance):
print(f'You pressed {instance.text}')
btn = Button(text='Click Me')
btn.bind(on_press=on_button_press)The KV Language
Kivy allows you to separate logic (Python) from presentation (KV Language).
myapp.py:
class LoginScreen(GridLayout):
passmyapp.kv:
<LoginScreen>:
cols: 2
Label:
text: 'User Name'
TextInput:
multiline: False