Sub-Commands#

parse_command_args#

Parse command-line arguments for subcommands, each associated with a different parser class

refer to parse_command_args()

Example usage

# example_1.py
class InitCmd(AbstractParser): # [1]
    DESCRIPTION = 'run init'
    name: str = argument('--name', required=True)

    def run(self):
        print(f"Initializing project: {self.name}")

# example_2.py
class BuildCmd(AbstractParser): # [1]
    DESCRIPTION = 'run build'
    release: bool = argument('--release')

    def run(self):
      print("Building in release mode" if self.release else "Building in debug mode")

# __main__.py
from argclz.commands import parse_command_args
parse_command_args( # [2]
    {'init': InitCmd,
    'build': BuildCmd}
 )

  1. sub-commands classes, which could be put at different python files.

  2. a function-interface entry point, which could be put at __main__.py to provide module-wise command-line interface.

  • Run the script with -h

usage: my_module [-h] {init,build} ...

options:
  -h, --help    show this help message and exit

commands:
  {init,build}
    init        run init
    build       run build

  • Run the script

$ python -m my_module init --name demo

  • Output

Initializing project: demo

sub_command_group#

The sub_command_group() helper lets you declare nested subcommands directly on a single AbstractParser class. Under the hood it creates a top‐level positional choice of subcommand names, then delegates parsing to the matching inner class.

class Main(AbstractParser):
    def run(self):
        print_help(self)

    command_group = sub_command_group()

    @command_group('a')
    class SubCommandA(AbstractParser):
        def run(self):
            print('do A')

    @command_group('b')
    class SubCommandB(AbstractParser):
        a: int = argument('-a', help='option for B')

        def run(self):
            print('do B', self.a)

Main().main()

  • Run the script with -h

usage: my_script.py [-h] {a,b} ...

positional arguments:
  {a,b}
    a
    b

  • Run the script

$ python my_script.py b -a 100

  • Output

do B 100