textual

Build terminal UI applications using Textual, a Python framework that provides widgets, screens, and reactive programming for creating interactive TUIs. Textual handles layout management, event loops, and terminal capabilities, letting you compose complex interfaces with CSS styling (TCSS) and manage state through reactive attributes.

Structure Textual apps by organizing screens as separate classes inheriting from Screen, each managing its own widgets and logic. Use the App lifecycle to navigate between screens, bind reactive attributes to trigger updates, and compose widgets hierarchically for maintainable, scalable terminal applications.

Yes, Textual supports CSS styling (TCSS) to control colors, layout, borders, and spacing of widgets. Write CSS rules targeting widget classes and IDs, enabling responsive, visually rich terminal interfaces without imperative styling code.

Use Textual's reactive programming model: define reactive attributes on your widget or screen, and watchers automatically trigger updates when values change. This decouples data changes from UI rendering, enabling smooth real-time updates in terminal dashboards and monitoring tools.

Test Textual apps using pytest with the Pilot testing framework, which simulates user interactions, captures widget state, and verifies output. Write tests to validate layout, event handling, reactive updates, and user workflows without manual terminal interaction.

Textual provides Container and related layout widgets to compose modals, sidebars, and multi-column layouts. Use screen push/pop mechanics for modal dialogs, bind events to user actions, and leverage TCSS to position and style overlay components elegantly.