CLI Development in Python

argparse is in the standard library and needs no dependencies, which matters for small scripts and system tools. Click defines commands with decorators, supports nested command groups and is the mature base for many well-known CLIs. Typer builds on Click and derives arguments and options from type hints, so a typed function becomes a command with little extra code. Cyclopts takes a similar type-hint approach and builds help text from your docstrings. prompt_toolkit handles interactive input with autocompletion, history and key bindings, and powers IPython and ptpython.

For output, Rich renders tables, syntax-highlighted code, progress bars, Markdown and readable tracebacks in the terminal. tqdm wraps any iterable in a progress bar, alive-progress adds animated bars with throughput and ETA, and colorama makes ANSI colors work on older Windows consoles. To build full terminal applications, Textual offers widgets, layouts and CSS-like styling from the makers of Rich, while urwid and asciimatics are older, stable alternatives.