from typing import Callable
from typing import List
import inspect


def get_arg_names(func: Callable) -> List[str]:
    """Get a list of all named arguments of a function (regular,
    keyword-only).

    func (Callable): The function
    RETURNS (List[str]): The argument names.
    """
    argspec = inspect.getfullargspec(func)
    return list(set([*argspec.args, *argspec.kwonlyargs]))