Tutorial 0 - Hello, world!

In this tutorial, you'll take a really simple "Hello, world!" program written in Python, convert it into a working project.

Setup

This tutorial assumes you've read and followed the instructions in /background/getting-started. If you've done this, you should have:

A tutorial directory,
An activated Python 3.5+ virtual environment,
Briefcase installed in that virtual environment,
Any platform-specific dependencies installed.

Start a new project

Let's get started by using the handy template briefcase-template:

$ pip install cookiecutter
$ cookiecutter https://github.com/beeware/briefcase-template

This will ask a bunch of questions of you. We'll use an app_name of "helloworld", a formal_name of "Hello World", using the Toga GUI toolkit. You can use the default values for the other questions (or update them to reflect your own name if you want).

You'll now have a few files in this folder, including a helloworld directory.

Check out what the provided helloworld/app.py file contains:

# If you are on macOS or Linux
$ cd helloworld
$ cat helloworld/app.py

# If you are on Windows command line
> cd helloworld
> type helloworld/app.py

import toga
from toga.style import Pack
from toga.style.pack import COLUMN, ROW


class HelloWorld(toga.App):
    def startup(self):
        # Create a main window with a name matching the app
        self.main_window = toga.MainWindow(title=self.name)

        # Create a main content box
        main_box = toga.Box()

        # Add the content on the main window
        self.main_window.content = main_box

        # Show the main window
        self.main_window.show()


def main():
    return HelloWorld('Hello World', 'com.example.helloworld')

Put it in a briefcase

Your project is now ready to use briefcase.

Windows

You must use Windows command line (cmd) to run this step. In case you have installed MingW32, Linux compatibility layer for Windows or similar, make sure it doesn't interfere with cmd environment.