Introducing the KV Language
Subject: Mobile Application Development (VU-CSS 223)
The KV language (kvlang) is a declarative markup language used for defining user interface layouts in Kivy applications. Its syntax closely resembles Python in structure and readability, similar to how HTML defines web interfaces. This design approach improves clarity, reduces code complexity, and enhances the overall user interface development experience.
You’ll be creating a new file to store the KV language in. Call it myapp.kv and save it in the same directory as main.py. Your .kv file should always have the same name as your app class, but converted to lowercase. Thus, MyApp will always look for its layout information in a file called myapp.kv.
When using a .kv file, UI code moves out of Python, so build() can simply return None.#main.py using .kv file for layout
from kivy.app import App
class MyApp(App):
def build(self):
return
MyApp().run()
myapp.kv file
IMPORTANT: name must match the App class#:kivy 2.0.0
Label:
text: "Welcome to my app"
color: 1, 0, 0, 1
font_size: 40
Naming rule (VERY IMPORTANT)App class → MyApp
KV file → myapp.kv (lowercase)
Kivy automatically loads the KV file if the name matches.
Why this is better- Cleaner Python code
- UI is easier to read and modify
- Matches real-world Kivy projects
- Ideal for teaching and scaling apps
By:
Vision University
Login to comment or ask question on this topic
Previous Topic Next Topic