Formalities, features, benefits and drawbacks

This project basically consists of a simple module dataparsers.py with few functions that allows to define typed arguments parsers in a single place, based on dataclasses.

Formalities

The main strategy of the module is based on the same approach of the package datargs, which consists in using the metadata attribute of the dataclass fields to store argument parameters. Some additional features of this project have already been contributed back upstream.

There are a lot of alternative libraries out there that do similar things. The README file of the datargs repository provides a good list for existing solutions and differences. I could also add to that list the libraries Python fire and the package dargparser, just to give few examples.

Features and benefits

Use this project if you want particular added features, such as:

  • Support for argument groups and mutually exclusive argument groups

  • Define all interface in one single place

  • More control over the interface display

  • More control over the argument flag -- creation

  • More similarity with argparse module

  • More simplicity

The simplicity is mentioned because it is just a simple module dataparsers.py that doesn’t have any additional dependency (it is pure Python) which can be downloaded directly and placed in your CLI scripts folder to import from.

In deed, the module consists of a 315 lines IPython code cell region (i.e., starts and ends with a #%% line comment block), that can also be placed on top of your “single file” CLI script to directly distribute. The used names are just the few provided functions, the stdlib imports and Class (a TypeVar).

Additionally, this project also provides a stub file (.pyi) that can be used by type checkers but, moreover, may be used by some code editors to give helper documentation including the related docs of argparse methods, which are also provided in this project’s documentation, for convenience. The stub file can be downloaded directly but it is installed with the module by default.

Drawbacks

Unlike the datargs package, dataparsers doesn’t support:

  • The library attrs (only works with pure python dataclasses)

  • Enums classes

  • Complex types (Sequences, Optionals, and Literals)

If you want any of these features, use the package datargs. If you need the added features of dataparsers, use this module instead.