quick-arguments 0.0.2

A simple argument parser

qargs (quick arguments)

qargs is an argument parser.

qargs is fast and easy to use. It is great for rapid prototyping and CLI utilities that need to minimize startup time.

qargs uses POSIX style argument syntax (mostly). It was implemented according to the syntax described by the The Open Group Base Specifications (Chapter 12: Utility conventions). The standard can be read here. It intentionally deviates from the standard by not implementing 12.1, 2a and 2b and 12.2, guideline 9.

Why write another argument parser?

Simply put, I don't like how other parsers work. I believe that they are needlessly difficult to use and most require too much boilerplate code. Because of this, I frequently found myself writing one-off parsers to meet my needs. I decided that instead of constantly reinventing the wheel, I needed more permanent solution; hence qargs.

Installation

qargs can be installed with pip: pip install qargs

Example Usage

qargs provides a single function, parse_args.

Called without any arguments, parse_args will do a few handy things for you:

• gather all arguments in the .operands attribute
• gather all files in the .files attribute
• gather all directories in the .directories attribute
• determine whether to read stdin with the .stdin attribute

import qargs

args = qargs.parse_args()

for f in args.files:
    # do a thing to each file

parse_args can be called with a specification to tell it what flags to look for.

import qargs

spec = [
    ['c', 'color'],
    ['v', 'verbose'],
]

args = qargs.parse_args(spec)

if args.color:
    # be colorful

if args.verbose:
    # be verbose

You can provide another value in the spec to capture arguments. If the value evaluates to a bool, the argument is blindly captured. If the value is callable, that callable is used to validate the argument.

import os
import qargs


def validate_config_file(f):
    return os.path.isfile(f) and f.endswith('.conf')


spec = [
    ['c', 'config-file', validate_config_file],
]

args = qargs.parse_args(spec)

with open(args.config_file, 'r') as cf
    # read config file