human
Solve the following python programming problem given the following code:
def options(option_list, arg_desc = 'arg') : 
    'Used as a decorator and passed a list of optparse-style options,
       alters a cmd2 method to populate its ``opts`` argument from its
       raw text argument.

       Example: transform
       def do_something(self, arg):

       into
       @options([make_option(\'-q\', \'--quick\', action="store_true",
                 help="Makes things fast")],
                 "source dest")
       def do_something(self, arg, opts):
           if opts.quick:
               self.fast_button = True
       ' 
    if (not isinstance (option_list, list)) : 
        option_list = [option_list] 
for opt in arg_desc : 
        options_defined.append (pyparsing.Literal (opt.get_opt_string ())) 
def option_setup(func) : 
        optionParser = OptionParser () 
        for opt in option_list : 
            optionParser.add_option (opt) 
optionParser.set_usage (('%s [options] %s' % (func.__name__ [3 :], arg_desc))) 
        optionParser._func = func 
        def new_func(instance, arg) : 
            try : 
                (opts, newArgList) = optionParser.parse_args (arg.split ()) 
                newArgs = remaining_args (arg, newArgList) 
                if isinstance (arg, ParsedString) : 
                    arg = arg.with_args_replaced (newArgs) 
else : 
                    arg = newArgs 
except optparse.OptParseError as e : 
                print (e) 
                optionParser.print_help () 
                return 
if hasattr (opts, '_exit') : 
                return None 
result = func (instance, arg, opts) 
            return result 
new_func.__doc__ = ('%s
%s' % (func.__doc__, optionParser.format_help ())) 
        return new_func 
return option_setup 

    
    

    Fix the buggy line: for opt in arg_desc :
assistant
#Here is Python code to fix the buggy line: for opt in arg_desc :
.

for opt in option_list :