def pypackable(name, pytype, format):
 (size, items) = _formatinfo(format)
 return type(Packable)(name, (pytype, Packable), {'_format_': format, '_size_': size, '_items_': items})

def pypackable ( name , pytype , format ) : ( size , items ) = _formatinfo ( format ) return type ( Packable ) ( name , ( pytype , Packable ) , { '_format_' : format , '_size_' : size , '_items_' : items } )
create a "mix-in" class with a python type and a packable with the given struct format .