argsy

Tiny wrapper for Python's argparse package with YAML-based cli configuration.

Overview

The argsy package aims to make CLI argument configuration and parsing declarative and simple, while still leveraging Python's argparse package to handle the parsing details and user help messaging.

Configuration supports declarative configuration of:

1. top-level position args, options / flags
2. a single tier of subcommands
3. position args, options / flags for each subcommand
4. support for setting default values for options / flags
5. partial nvars support for capturing multiple input values
6. support for the action directive (for things like toggling booleans)

Getting Started

Install argsy

pip install argsy>=1.0.0

Define your program structure

CLI arguments are define as either:

1. a YAML file or string, or
2. a Python dict object

YAML file

#
# my_cli_args.yml
# 
program:
  name: my_program
  descripton: "About what my_program does."
  args:
    option1:
      cmd_type: option
      flags: '-o|--option1'
      help: "Short text about the option."
      required: true

#
# my_program.py
# 
from argsy import Argsy

argsy_parser = Argsy(config_file_name="my_cli_args.yml")
parsed_args = argsy_parser.parse_args(sys.argv[1:])

# User runs: 
#     my_program -o USER_PROVIDED_OPTION_VALUE
# 
# Resulting 'parsed_args':
# {
#   'cmd': None, 
#   'args': {
#     'option1': USER_PROVIDED_OPTION_VALUE
#   }
# }

YAML String

#
# my_program.py
# 
from argsy import Argsy

CLI_ARGS = """
program:
  name: my_program
  descripton: "About what my_program does."
  args:
    option1:
      cmd_type: option
      flags: '-o|--option1'
      help: "Short text about the option."
      required: true
"""

argsy_parser = Argsy(config_str=CLI_ARGS)
parsed_args = argsy_parser.parse_args(sys.argv[1:])

# User runs: 
#     my_program -o USER_PROVIDED_OPTION_VALUE
# 
# Resulting 'parsed_args':
# {
#   'cmd': None, 
#   'args': {
#     'option1': USER_PROVIDED_OPTION_VALUE
#   }
# }

Python Dictionary

#
# my_program.py
# 
from argsy import Argsy

CLI_ARGS = dict(
    program=dict(
        name='my_program',
        description='About what my_program does.',
        args=dict(
            option1=dict(
                cmd_type='option',
                flags='-o|--option1',
                help='Short text about the option.',
                required=True
            )
        )
    )
)

argsy_parser = Argsy(config_dict=CLI_ARGS)
parsed_args = argsy_parser.parse_args(sys.argv[1:])

# User runs: 
#     my_program -o USER_PROVIDED_OPTION_VALUE
# 
# Resulting 'parsed_args':
# {
#   'cmd': None, 
#   'args': {
#     'option1': USER_PROVIDED_OPTION_VALUE
#   }
# }