def accepts(exception,**types):     def check_accepts(f):         assert len(types) == f.func_code.co_argcount,         'accept number of arguments not equal with function number of arguments in "%s"' % f.func_name         def new_f(*args, **kwds):             for i,v in enumerate(args):                 if types.has_key(f.func_code.co_varnames[i]) and                     not isinstance(v, types[f.func_code.co_varnames[i]]):                     raise exception("arg '%s'=%r does not match %s" %                         (f.func_code.co_varnames[i],v,types[f.func_code.co_varnames[i]]))                     del types[f.func_code.co_varnames[i]]             for k,v in kwds.iteritems():                 if types.has_key(k) and not isinstance(v, types[k]):                     raise exception("arg '%s'=%r does not match %s" %                         (k,v,types[k]))             return f(*args, **kwds)         new_f.func_name = f.func_name         return new_f     return check_accepts def exmaple():     @accepts(Exception,a=int,b=list,c=(str,unicode))     def test(a,b=None,c=None)         print 'ok'     test(13,c=[],b='df')