1 # Python Development in QMK
3 This document gives an overview of how QMK has structured its python code. You should read this before working on any of the python code.
7 There are two places scripts live in QMK: `qmk_firmware/bin` and `qmk_firmware/util`. You should use `bin` for any python scripts that utilize the `qmk` wrapper. Scripts that are standalone and not run very often live in `util`.
9 We discourage putting anything into `bin` that does not utilize the `qmk` wrapper. If you think you have a good reason for doing so please talk to us about your use case.
13 Most of the QMK python modules can be found in `qmk_firmware/lib/python`. This is the path that we append to `sys.path`.
15 We have a module hierarchy under that path:
17 * `qmk_firmware/lib/python`
18 * `milc.py` - The CLI library we use. Will be pulled out into its own module in the future.
19 * `qmk` - Code associated with QMK
20 * `cli` - Modules that will be imported for CLI commands.
21 * `errors.py` - Errors that can be raised within QMK apps
22 * `keymap.py` - Functions for working with keymaps
26 We have a CLI wrapper that you should utilize for any user facing scripts. We think it's pretty easy to use and it gives you a lot of nice things for free.
28 To use the wrapper simply place a module into `qmk_firmware/lib/python/qmk/cli`, and create a symlink to `bin/qmk` named after your module. Dashes in command names will be converted into dots so you can use hierarchy to manage commands.
30 When `qmk` is run it checks to see how it was invoked. If it was invoked as `qmk` the module name is take from `sys.argv[1]`. If it was invoked as `qmk-<module-name>` then everything after the first dash is taken as the module name. Dashes and underscores are converted to dots, and then `qmk.cli` is prepended before the module is imported.
32 The module uses `@cli.entrypoint()` and `@cli.argument()` decorators to define an entrypoint, which is where execution starts.
36 We have provided a QMK Hello World script you can use as an example. To run it simply run `qmk hello` or `qmk-hello`. The source code is listed below.
41 @cli.argument('-n', '--name', default='World', help='Name to greet.')
42 @cli.entrypoint('QMK Python Hello World.')
44 cli.echo('Hello, %s!', cli.config.general.name)