CLI in Python

#cli

Terminal output

https://bernsteinbear.com/blog/python-parallel-output/

CLI frameworks

From the standard library

1. argparse: argparse is a built-in Python module that provides a way to parse command-line arguments. It’s easy to use and provides a lot of flexibility, making it a popular choice for writing command-line interfaces in Python.
   • → More info + tutorial: Argparse

Frameworks based on argparse

See Argparse#Usage in higher-level CLI frameworks

Click family

1. Click: a popular Python CLI framework that is built on top of optparse. It provides a more user-friendly interface than argparse and adds several useful features, such as command grouping, automatic help page generation, and more.
2. Typer: a relatively new Python CLI framework that is also built on top of Click. It provides a simpler interface than Click and aims to be very easy to use. Typer is particularly well-suited for creating CLI tools that interact with APIs.

Click is internally based on optparse instead of argparse. This is an implementation detail that a user does not have to be concerned with. Click is not based on argparse because it has some behaviors that make handling arbitrary command line interfaces hard:
- argparse has built-in behavior to guess if something is an argument or an option. This becomes a problem when dealing with incomplete command lines; the behaviour becomes unpredictable without full knowledge of a command line. This goes against Click’s ambitions of dispatching to subparsers.
- argparse does not support disabling interspersed arguments. Without this feature, it’s not possible to safely implement Click’s nested parsing.

Others

1. docopt: docopt is another Python package that provides a way to define a CLI by describing it in a docstring. It automatically generates the parser and makes it easy to define complex command-line interfaces.

Console utilities

• Rich (lots of - maybe to many - features)
• Colorama
• https://pypi.org/project/wasabi/ “wasabi: A lightweight console printing and formatting toolkit”

CLI best practices

• https://clig.dev/
• https://medium.com/jit-team/guidelines-for-creating-your-own-cli-tool-c95d4af62919
• https://zapier.com/engineering/how-to-cli/
• https://hackmd.io/@arturtamborski/cli-best-practices
• https://eng.localytics.com/exploring-cli-best-practices/

Older notes

Existing frameworks:

• Fire: https://github.com/google/python-fire
• Click: https://pypi.org/project/click/
• Typer (= click extension, driven by type annotations)
• Cleo: https://github.com/sdispater/cleo

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More

• Clint (obsolete) = mostly convenience functions.

Page last modified: 2024-03-08 12:47:25