Rich is a Python library for rendering rich text, beautiful formatting, and advanced content to the terminal. It provides a Console class as its central abstraction, which manages terminal capabilities (color systems, width, encoding) and renders a composable hierarchy of 'renderables' — objects implementing the __rich_console__ protocol that yield Segment tuples (text, style, control codes). The architecture is a monolithic library with clean internal modularity: the Console orchestrates rendering, Segment is the low-level output primitive, and higher-level renderables (Table, Tree, Markdown, Syntax, Progress, Layout, Live) compose into each other via the protocol. Key entry points are the module-level print/inspect/print_json functions (backed by a global Console singleton), the Console class for explicit control, and CLI modules (python -m rich.syntax, python -m rich.markdown, etc.). The library handles cross-platform terminal differences including Windows legacy console API calls via ctypes, Jupyter notebook HTML rendering, and Unicode width calculations across 21 Unicode versions. External dependencies are minimal: pygments for syntax highlighting and markdown-it-py for Markdown parsing. The codebase demonstrates exceptional craftsmanship in its terminal rendering pipeline, careful handling of edge cases (CJK width, emoji variants, control codes, broken file-like objects), and a well-designed protocol system that enables arbitrary composition of renderables. The Segment-based rendering architecture is both performant and elegant, allowing style application, line splitting, and cell-width calculations to be composed as transformations over segment sequences.
Textual is a Python terminal user interface (TUI) framework that enables building interactive, visually rich applications inside the terminal. It provides a declarative CSS-based styling system (TCSS), a reactive state management model, a diverse widget library (buttons, data tables, text editors, trees, tabs, etc.), and an asynchronous event-driven architecture. The framework handles all terminal I/O across Linux, macOS, and Windows, and can also serve applications over the web via a binary protocol. Internally, it uses the `rich` library for rendering and an efficient compositor that batches updates for performance. The primary entry point is the `App` class in `src/textual/app.py`, from which users subclass and compose widgets via `compose()` methods. Styling can be embedded as `DEFAULT_CSS` or loaded from external `.tcss` files. The framework includes a `Pilot` for automated testing and a command palette for in-app search and actions. Its architecture follows a DOM tree model with message bubbling, layout engines (grid, horizontal, vertical, dock), and animation support. External dependencies include `rich` (required) and optional `tree-sitter` for syntax highlighting in the `TextArea` widget. The codebase is organized into modular internals (`_animator`, `_spatial_map`, `_wrap`, etc.) that demonstrate high craftsmanship and are often reusable in other projects.
Spiel is a terminal-based framework for creating and presenting slide decks using Python. It enables users to define slides as functions that return renderable objects (via Rich), and presents them in a navigable terminal user interface built with Textual. The framework supports features like live reloading during development, slide transitions, and dynamic content generation through a trigger system. The architecture centers around a `Deck` class that manages a sequence of `Slide` objects. Each slide's content is defined by a function that can optionally receive a `Triggers` object for time-based or interactive effects. The presentation is driven by a custom Textual application (`SpielApp`) that handles user input, screen transitions (including slide-to-slide animations), and automatic reloading of the deck when source files change. Key components include the CLI for launching presentations, a flexible slide definition system, and reusable widgets for rendering content such as syntax-highlighted code and images. Notable reusable components include the `Triggers` class for managing interactive state, the `Swipe` transition for slide animations, the `Image` widget for terminal image display, and a set of utility functions (`clamp`, `filter_join`, `chunks`) that solve common programming problems. These components are designed with low coupling and could be extracted for use in other projects with minimal modification.