Tutorial 1 - Your first app¶

We\'re ready to create our first application.

Install the BeeWare tools¶

First, we need to install Briefcase. Briefcase is a BeeWare tool that can be used to package your application for distribution to end users - but it can also be used to bootstrap a new project. Make sure you\'re in the beeware-tutorial directory you created in Tutorial 0 <tutorial-0>, with the beeware-venv virtual environment activated, and run:

:::::::: {.tabs} ::: {.group-tab} macOS

(beeware-venv) $ python -m pip install briefcase

:::

:::: {.group-tab} Linux

(beeware-venv) $ python -m pip install briefcase

::: {.admonition} Possible errors during installation

If you see errors during installation, it\'s almost certainly because some of the system requirements haven\'t been installed. Make sure you have installed all the platform pre-requisites <install-dependencies>. ::: ::::

:::: {.group-tab} Windows

(beeware-venv) C:\...>python -m pip install briefcase

::: {.admonition} Possible errors during installation

It is important that you use python -m pip, rather than a bare pip. Briefcase needs to ensure that it has an up-to-date version of pip and setuptools, and a bare invocation of pip can\'t self-update. If you want to know more, Brett Cannon has a detailed blog post about the issue. ::: :::: ::::::::

Bootstrap a new project¶

Let\'s start our first BeeWare project! We\'re going to use the Briefcase new command to create an application called Hello World. Run the following from your command prompt:

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(beeware-venv) $ briefcase new

:::

::: {.group-tab} Linux

(beeware-venv) $ briefcase new

:::

::: {.group-tab} Windows

(beeware-venv) C:\...>briefcase new

::: ::::::

Briefcase will ask us for some details of our new application. For the purposes of this tutorial, use the following:

Formal Name - Accept the default value: Hello World.
App Name - Accept the default value: helloworld.
Bundle Identifier - If you own your own domain, enter that domain in reversed order. (For example, if you own the domain \"cupcakes.com\", enter com.cupcakes as the bundle). If you don\'t own your own domain, accept the default bundle (com.example).
Project Name - Accept the default value: Hello World.
Description - Accept the default value (or, if you want to be really creative, come up with your own description!)
Author - Enter your own name here.
Author\'s Email - Enter your own email address. This will be used in the configuration file, in help text, and anywhere that an email is required when submitting the app to an app store.
Application URL - The URL of the landing page for your application. Again, if you own your own domain, enter a URL at that domain (including the https://). Otherwise, just accept the default URL (https://example.com/helloworld). This URL doesn\'t need to actually exist (for now); it will only be used if you publish your application to an app store.
Project License - Accept the default license (BSD). This won\'t affect anything about the operation of the tutorial, though - so if you have particularly strong feelings about license choice, feel free to choose another license.
GUI framework - Accept the default option, Toga (BeeWare\'s own GUI toolkit).

Briefcase will then generate a project skeleton for you to use. If you\'ve followed this tutorial so far, and accepted the defaults as described, your file system should look something like:

beeware-tutorial/
├── beeware-venv/
│   └── ...
└── helloworld/
    ├── CHANGELOG
    ├── LICENSE
    ├── pyproject.toml
    ├── README.rst
    ├── src/
    │   └── helloworld/
    │       ├── app.py
    │       ├── __init__.py
    │       ├── __main__.py
    │       └── resources/
    │           └── README
    └── tests/
        ├── helloworld.py
        ├── __init__.py
        └── test_app.py

This skeleton is actually a fully functioning application without adding anything else. The src folder contains all the code for the application, the tests folder contains an initial test suite, and the pyproject.toml file describes how to package the application for distribution. If you open pyproject.toml in an editor, you\'ll see the configuration details you just provided to Briefcase.

Now that we have a stub application, we can use Briefcase to run the application.

Run the app in developer mode¶

Move into the helloworld project directory and tell briefcase to start the project in Developer (or dev) mode:

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(beeware-venv) $ cd helloworld
(beeware-venv) $ briefcase dev

[hello-world] Installing requirements...
...

[helloworld] Starting in dev mode...
===========================================================================

:::

::: {.group-tab} Linux

(beeware-venv) $ cd helloworld
(beeware-venv) $ briefcase dev

[hello-world] Installing requirements...
...

[helloworld] Starting in dev mode...
===========================================================================

:::

::: {.group-tab} Windows

(beeware-venv) C:\...>cd helloworld
(beeware-venv) C:\...>briefcase dev

[hello-world] Installing requirements...
...

[helloworld] Starting in dev mode...
===========================================================================

::: ::::::

This should open a GUI window:

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Hello World Tutorial 1 window, on macOS :::

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Hello World Tutorial 1 window, on Linux :::

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Hello World Tutorial 1 window, on Windows

::: {.admonition} Invalid requirements or pip unable to connect

If you encounter the error:

Unable to install requirements. This may be because one of your
requirements is invalid, or because pip was unable to connect
to the PyPI server.

Confirm that you are running a version of python that this tutorial supports <install-python>.

If your version of python is not a supported version, you will have to restart the tutorial. ::: :::: :::::::

Close the application - either by pressing the close button on the application window, by selecting Quit/Exit from the application\'s menu, or by typing Ctrl+C in the terminal where you ran briefcase dev - and you\'re done! Congratulations - you\'ve just written a standalone, native application in Python!

Next steps¶

We now have a working application, running in developer mode. Now we can add some logic of our own to make our application do something a little more interesting. In Tutorial 2 <tutorial-2>{.interpreted-text role="doc"}, we\'ll put a more useful user interface onto our application.