This is a very simple Python package that allows one to create argparse's subcommands via function decorators.

Create a SubDec object:

import argparse_subdec

# Create the object to collect subcommands via decorators
sd = argparse_subdec.SubDec()

Now, we can define our subcommands. We define a subcommand by decorating a function with method calls to sd, like below:

@sd.add_argument('--option', default='123')
@sd.add_argument('--another')
def foo(args):
    print(f'foo subcommand: --option={args.option!r} and --another={args.another!r}')

You can use any method name that you would use in a subparser. In our example above, we used add_argument, probably most commonly used. When creating the subparsers, sd will replay those calls to the created subparser for the foo subcommand.

Since using sd.add_argument() is so common, there is an alias to save some keystrokes. The example below is the equivalent of the above using the alias:

@sd.arg('--option', default='123')
@sd.arg('--another')
def foo(args):
    print(f'foo subcommand: --option={args.option!r} and --another={args.another!r}')

In the example below we define a second subcommand, which will be named foo-bar:

@sd.cmd(prefix_chars=':')
@sd.add_argument('positional_arg', type=int)
def foo_bar(args):
    print(f'foo-bar subcommand: {args.positional_arg!r}')

Note that we use a special decorator, sd.cmd, which makes sd pass all of its arguments down to add_parser() when creating the subparser for foo-bar.

Once our subcommands are defined, we must call sd.create_parsers() in order to effectively create the subparsers:

parser = argparse.ArgumentParser()
subparsers = parser.add_subparsers()
sd.create_parsers(subparsers)

The following is example of how we would call the subcommands:

args = parser.parse_args(['foo', '--another', 'hello'])
args.fn(args) # The subcommand function is assigned to ``args.fn`` by default
# Outputs: foo subcommand: --option='123' and --another='hello'

For more details about the API, check out the subdec module.

Via pip:

pip install argparse-subdec