argster

Short and sweet command line argument parser for Python. Designed for direct script embedding.

Features

• command based interface
• command aliases (shorthands)
• flags / options
• flag grouping
• argument aliases
• small: 979b / 38 loc w/o comments

Usage

Basic

# app.py
import argster
from sys import argv

args = argster.parse(argv[1:])
print(args)

# alternatively:
# from argster import argster
# args = argster(argv[1:])

Result

$ app.py cmd -abc=3 -d=4 --foo --bar=baz

{
    '$': ['cmd'],
    'a': True,
    'b': True,
    'c': '3',
    'd': '4',
    'foo': True,
    'bar': 'baz'
}

Commands

Arguments that do not start with - are recognized as commands, or free values, and stored in $ sublist (see below).

Aliases and defaults

• aliases and defaults are set in one go using dict as a second param
• flags (options without a value ie -f or --foo) always evaluate to True
• defaults are only used in absence of a param
• commands don't use default values and should be set to None

args = argster.parse(sys.argv[1:], {
    # short|long: default
    'cmd|command': None,
    'sub|subcommand': None,
    'f|foo': 'fail',
    'b|bar': False,
    'l|leet': 1337,
})

Result

$ app.py cmd sub -f -b=baz

{
    '$': ['command', 'subcommand'],
    'foo': True,
    'bar': 'baz',
    'leet': 1337
}

Cheatsheet

cmd      -- command
-a       -- a=True
-a=1     -- a="1"
-abc     -- a=True, b=True, c=True
-abc=3   -- a=True, b=True, c="3"
--opt    -- opt=True
--opt=3  -- opt="3"
-x       -- when aliased => expanded=True

Direct embedding

Minified version is provided in argster-min.py file, which has comments and empty lines removed.

Limitations

• no type casts
• no checks for required values
• no complains over superfluous args
• no validation
• no arrays, use delimiters
• no multi args, use delimiters
• no lookahead, use explicit = for assignment
• no auto help pages

Prior art

Argster is inspired by node's minimist module.

License

MIT