coding-python-textual

Create a class extending textual.app.App, yield widgets from compose(), and call run(). Style the interface with Textual CSS via CSS_PATH, and use reactive attributes with watch_ methods so widgets update automatically when state changes.

Apply the align style to the container, not the child: set 'align: center middle' on the Screen or wrap each widget in a Center container. Align works on a container's children, which is a common source of confusion.

DataTable.add_column(width=N) hard-clips text at N cells with no ellipsis, and text-overflow never reaches cells because they render through Rich rather than the CSS box. Truncate in your own cell text if you want a marker.

Widget.check_action() is three-valued: returning False hides the binding from the footer and palette, None shows it greyed out, and True allows it. Return None instead of False when you want the action visible but disabled.

Textual has no built-in image support yet; the rich-pixels project offers a Rich renderable for images. It deliberately avoids the 16 ANSI theme colors, using 16.7 million colors for consistent cross-platform rendering, with an ansi_color opt-in on App.

Textual provides a Pilot API for testing: run the app in test mode with run_test(), then simulate key presses and clicks against widgets. See the testing guide referenced in the documentation index for full details.