Linux Tutorial 0 - Hello, world!

In this tutorial, you’ll take a really simple “Hello, world!” program written in Python, convert it into a working Linux project.

Setup

This tutorial assumes you’ve read and followed the instructions in Getting Started. This Tutorial is for Linux Users! * A tutorial directory, * An activated Python 3 virtual environment, * Briefcase installed in that virtual environment,

Start a new project

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

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

This will ask a bunch of questions of you. We’ll use an app_name of “tutorial_0”, and a formal_name of “Tutorial 0”. Set the other values as you like

You’ll now have a few files in this folder, including tutorial_0.

Check out what the provided tutorial_0/app.py file contains:

(BeeWare)user$ cd tutorial_0
(BeeWare)user$ cat tutorial_0/app.py
def main():
    # This needs to return an object that has a main_loop() method.
    return None

This won’t do much as it is, but we can make it useful.

Add this into the app.py to make it useful:

class MyApp:
    def main_loop(self):
        print("Hello world")


def main():
    return MyApp()

Create an Linux project

It is all ready for using briefcase. You can invoke it, using:

$ python setup.py linux

to create the Linux app.

Open the project

There is a new folder in your project called ‘linux’, which contains the project (tutorial_0). You can open the application by running:

./linux/tutorial_0

The app should run like this! .. code-block:: bash

$ ./linux/tutorial_0
Hello World!

And that is all, you created your first Linux python app!