Hello world¶

If you don’t know how to start with Python for Android, here is a simple tutorial for creating an UI using Kivy, and make an APK with this project.

Note

Don’t forget that Python for Android is not Kivy only, and you might want to use other toolkit libraries. When other toolkits will be available, this documentation will be enhanced.

Let’s create a simple Hello world application, with one Label and one Button.

Ensure you’ve correctly installed and configured the project as said in the Prerequisites
Create a directory named helloworld:
```
mkdir helloworld
cd helloworld
```

Create a file named main.py, with this content:

import kivy
kivy.require('1.0.9')
from kivy.lang import Builder
from kivy.uix.gridlayout import GridLayout
from kivy.properties import NumericProperty
from kivy.app import App

Builder.load_string('''
<HelloWorldScreen>:
    cols: 1
    Label:
        text: 'Welcome to the Hello world'
    Button:
        text: 'Click me! %d' % root.counter
        on_release: root.my_callback()
''')

class HelloWorldScreen(GridLayout):
    counter = NumericProperty(0)
    def my_callback(self):
        print 'The button has been pushed'
        self.counter += 1

class HelloWorldApp(App):
    def build(self):
        return HelloWorldScreen()

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

Go to the python-for-android directory
Create a distribution with kivy:
```
./distribute.sh -m kivy
```
Go to the newly created default distribution:
```
cd dist/default
```
Plug your android device, and ensure you can install development application

Build your hello world application in debug mode:

./build.py --package org.hello.world --name "Hello world" \
--version 1.0 --dir /PATH/TO/helloworld debug installd

Take your device, and start the application!
If something goes wrong, open the logcat by doing:
```
adb logcat
```

The final debug APK will be located in bin/hello-world-1.0-debug.apk.

If you want to release your application instead of just making a debug APK, you must:

Generate a non-signed APK:

./build.py --package org.hello.world --name "Hello world" \
--version 1.0 --dir /PATH/TO/helloworld release

Continue by reading http://developer.android.com/guide/publishing/app-signing.html