util.py 文件源码

def _apply_defaults(bound):
    """Set default values for missing arguments.

    For variable-positional arguments (*args) the default is an
    empty tuple.

    For variable-keyword arguments (**kwargs) the default is an
    empty dict.

    Args:

        bound (:class:`inspect.BoundArguments`): A BoundArguments object.

    Returns:

        None

    """
    arguments = bound.arguments

    new_arguments = []
    for name, param in bound._signature.parameters.items():
        try:
            new_arguments.append((name, arguments[name]))
        except KeyError:
            if param.default is not _empty:
                val = param.default
            elif param.kind is _VAR_POSITIONAL:
                val = ()
            elif param.kind is _VAR_KEYWORD:
                val = {}
            else:
                # This BoundArguments was likely produced by
                # Signature.bind_partial().
                continue
            new_arguments.append((name, val))

    bound.arguments = OrderedDict(new_arguments)