def parse_arg(f, kwd, offset=0):
    """
    convert dictionary of keyword argument and value to positional argument
    equivalent to::

        vnames = describe(f)
        return tuple([kwd[k] for k in vnames[offset:]])

    """
    vnames = describe(f)
    return tuple([kwd[k] for k in vnames[offset:]])
convert dictionary of keyword argument and value to positional argument
    equivalent to::

        vnames = describe(f)
        return tuple([kwd[k] for k in vnames[offset:]])