Example of livereload in python: Creates a file watcher that runs `python build_assets.py`, a utility based on webassets package whenever a css or js file is edited. It bundles a bunch of our CSS files into a single minified one and does the same for our JS files.

asset_bundler_watcher.py

from pathlib import Path

# Creates a file watcher that runs `python build_assets.py`, a utility based on
# webassets package whenever a css or js file is edited. It bundles a bunch of
# our CSS files into a single minified one and does the same for our JS files.


def main():
    # Only import this if we run it, don't let the webframework try to pull it in prod.
    import livereload.server
    
    # This file lives in the webroot/bin/ folder.
    root_folder = Path(__file__).parent.parent.absolute()
    static_folder = root_folder / "static"

    css_folder = static_folder / 'css' / '*.css'
    js_folder = static_folder / 'js' / '*.js'

    python_exe = root_folder.parent / 'venv' / 'bin' / 'python'
    cmd = Path(__file__).parent / 'build_assets.py'
    shell = livereload.shell(python_exe.as_posix() + ' ' + cmd.as_posix())

    server = livereload.server.Server()
    server.watch(css_folder.as_posix(), shell, delay=0.5)
    server.watch(js_folder.as_posix(), shell, delay=0.5)
    server.serve(debug=False, root=root_folder.as_posix())


if __name__ == '__main__':
    main()