def _resolve_subparsers()

in nubia/internal/typing/argparse.py [0:0]

• 14 lines of code
• 4 McCabe index (conditional complexity)

def _resolve_subparsers(parser):
    # a subparser resulting from parser.add_subparsers was inputted
    if isinstance(parser, argparse._SubParsersAction):
        subparsers = parser
    # an actual parser was inputted
    elif isinstance(parser, argparse.ArgumentParser):
        # Unfortunately there is no method to get the current subparsers apart
        # from reading the private property. Trying to call
        # parser.add_subparsers a second time will result in a SystemExit error.
        # Also when you call parser.add_subparsers you get an Action object,
        # that is listed under parser._subparsers._actions.
        # Argparse is a beautiful thing
        if getattr(parser, "_subparsers", None):
            subparsers = parser._subparsers._actions[-1]
        else:
            subparsers = parser.add_subparsers(dest="_cmd", help="Subcommand to run")
    else:
        raise ValueError(
            "Expected an argparse.ArgumentParser or an "
            "argparse._SubParsersAction as input"
        )

    return subparsers