nzbToMedia/libs/win/jaraco/ui/cmdline.py
2022-11-29 00:44:47 -05:00

77 lines
2.2 KiB
Python

import argparse
from jaraco.classes import meta
from jaraco import text # type: ignore
class Command(metaclass=meta.LeafClassesMeta):
"""
A general-purpose base class for creating commands for a command-line
program using argparse. Each subclass of Command represents a separate
sub-command of a program.
For example, one might use Command subclasses to implement the Mercurial
command set::
class Commit(Command):
@staticmethod
def add_arguments(cls, parser):
parser.add_argument('-m', '--message')
@classmethod
def run(cls, args):
"Run the 'commit' command with args (parsed)"
class Merge(Command): pass
class Pull(Command): pass
...
Then one could create an entry point for Mercurial like so::
def hg_command():
Command.invoke()
"""
@classmethod
def add_subparsers(cls, parser):
subparsers = parser.add_subparsers()
[cmd_class.add_parser(subparsers) for cmd_class in cls._leaf_classes]
@classmethod
def add_parser(cls, subparsers):
cmd_string = text.words(cls.__name__).lowered().dash_separated()
parser = subparsers.add_parser(cmd_string)
parser.set_defaults(action=cls)
cls.add_arguments(parser)
return parser
@classmethod
def add_arguments(cls, parser):
pass
@classmethod
def invoke(cls):
"""
Invoke the command using ArgumentParser
"""
parser = argparse.ArgumentParser()
cls.add_subparsers(parser)
args = parser.parse_args()
args.action.run(args)
class Extend(argparse.Action):
"""
Argparse action to take an nargs=* argument
and add any values to the existing value.
>>> parser = argparse.ArgumentParser()
>>> _ = parser.add_argument('--foo', nargs='*', default=[], action=Extend)
>>> args = parser.parse_args(['--foo', 'a=1', '--foo', 'b=2', 'c=3'])
>>> args.foo
['a=1', 'b=2', 'c=3']
"""
def __call__(self, parser, namespace, values, option_string=None):
getattr(namespace, self.dest).extend(values)