A small tour of PythonNative: four tabs inside a native stack, typed screens, a theme with light and dark variants, and a setting that's saved on the device.

• app/main.py defines the navigators as module-level values. Tabs (Home, Layout, List, and Settings) is the first screen of the Root stack, and the Showcase, Forms, and Async Demo screens push on top of it with calls like nav.push(ShowcaseScreen(message="Hi")).
• app/theme.py subclasses pn.Theme to add the demo's own color tokens and defines the styles every screen shares. App passes the light and dark themes to pn.ThemeProvider, so the screens and the navigation bars follow the system appearance.
• app/preferences.py saves the appearance chosen on the Settings tab (System, Light, or Dark) with pn.use_persisted_state and applies it at launch.
• app/screens/ holds one file per screen. They cover state and effects, flex layout, a virtualized FlatList, native alerts, animations, forms with a title that follows the input, and async data with Suspense, use_query, and use_mutation.

From this directory, install the example's dependencies (the preview imports your real app code), then launch it. This app declares emoji in [requirements].packages, so install it locally for the preview:

pip install emoji
pn preview

A browser tab opens running app/main.py's App in a phone frame. Edit any component under app/, save, and the page Fast Refreshes in place (no simulator or device needed). See the Browser preview guide.

Leave pn preview running and, in another terminal:

pn run ios
# or
pn run android

The debug build connects to the same dev server, so saves under app/ Fast Refresh it too and its logs show up in the pn preview terminal. See the Development workflow.

From this directory, the app passes strict type checking and the hook linter:

uv run mypy --strict app
uv run pn lint app