simple-parsing 0.0.9

A small utility for simplifying and cleaning up argument parsing scripts.

Simple, Elegant Argument Parsing

simple-parsing helps you parse arguments easier. Using the power of Python dataclasses, you can now define groups of argparse arguments in a way that is easier for people to read, write, and maintain, while using fewer lines of code. Argument groups are reusable and extendable, and can even be nested!

# examples/demo.py
from dataclasses import dataclass
import simple_parsing

parser = simple_parsing.ArgumentParser()
parser.add_argument("--foo", type=int, default=123, help="foo help string")

@dataclass
class Options:
    """ Help string for this group of command-line arguments """
    log_dir: str                # Help string for a required str argument
    learning_rate: float = 1e-4 # Help string for a float argument

parser.add_arguments(Options, dest="options")

args = parser.parse_args("--log_dir logs --foo 123".split())
print(args.foo)     # 123
print(args.options) # Options(log_dir='logs', learning_rate=0.0001)

Additionally, simple-parsing makes it easier to document your arguments by generating "--help" strings directly from your source code!

$ python examples/demo.py --help
usage: demo.py [-h] [--foo int] --log_dir str [--learning_rate float]

optional arguments:
  -h, --help            show this help message and exit
  --foo int             foo help string (default: 123)

Options ['options']:
  Help string for this group of command-line arguments

  --log_dir str         Help string for a required str argument (default:
                        None)
  --learning_rate float
                        Help string for a float argument (default: 0.0001)

installation

pip install simple-parsing

Project GitHub Repository

Examples

API Documentation (Under construction)

Features

• Automatic "--help" strings

  As developers, we want to make it easy for people coming into our projects to understand how to run them. However, a user-friendly --help message is often hard to write and to maintain, especially as the number of arguments increases.

  With simple-parsing, your arguments and their decriptions are defined in the same place, making your code easier to read, write, and maintain.

• Modular, Reusable Arguments (no more copy-pasting!)

  When you need to add a new group of command-line arguments similar to an existing one, instead of copy-pasting a block of argparse code and renaming variables, you can reuse your argument class, and let the ArgumentParser take care of adding relevant prefixes to the arguments for you:

  parser.add_arguments(Options, dest="train")
  parser.add_arguments(Options, dest="valid")
  args = parser.parse_args()
  train_options: Options = args.train
  valid_options: Options = args.valid
  print(train_options)
  print(valid_options)
  

  $ python examples/demo.py \
      --train.experiment_name "training" \
      --valid.experiment_name "validation"
  Options(experiment_name='training', learning_rate=0.0001)
  Options(experiment_name='validation', learning_rate=0.0001)
  

  These prefixes can also be set explicitly, or not be used at all. For more info, take a look at the Prefixing Guide

• Inheritance! You can easily customize an existing argument class by extending it and adding your own attributes, which helps promote code reuse accross projects. For more info, take a look at the inheritance example

• Nesting!: Dataclasses can be nested within dataclasses, as deep as you need!

• Easy serialization: Since dataclasses are just regular classes, its easy to add methods for easy serialization/deserialization to popular formats like json or yaml.

• Easier parsing of lists and tuples: This is sometimes tricky to do with regular argparse, but simple-parsing makes it a lot easier by using the standard type annotations of the typing module to automatically convert the parsed values to the right type for you.

  As an added feature, by using these type annotations, simple-parsing allows you to parse nested lists or tuples, as can be seen in this example

• Enums support

• (More to come!)

Examples:

Additional examples for each of the above-mentioned features can be found in the the project repository.