Format an argument spec from the 4 values returned by getargspec. The first four arguments are (args, varargs, varkw, defaults). The other four arguments are the corresponding optional formatting functions that are called to turn names and values into strings. The ninth argument i
(args, varargs=None, varkw=None, defaults=None,
formatarg=str,
formatvarargs=lambda name: '*' + name,
formatvarkw=lambda name: '**' + name,
formatvalue=lambda value: '=' + repr(value),
join=joinseq)