Found a problem with the args of the Dictionary "items" function.

[Sungmin-Joo]

Current Results
in gpython

>>>> d_list = {'a' : 1, 'b' : 2}
>>>> for k, v in d_list.items("hi"):
>>>>     print(k,':',v)
a : 1
b : 2

in python

>>>> d_list = {'a' : 1, 'b' : 2}
>>>> for k, v in d_list.items("hi"):
>>>>     print(k,':',v)
Traceback (most recent call last):
  File "test.py", line 2, in <module>
    for k, v in d_list.items("hi"):
TypeError: items() takes no arguments (1 given)

gpython/py/dict.go

Lines 30 to 39 in af17d7d

	func init() {
	StringDictType.Dict["items"] = MustNewMethod("items", func(self Object, args Tuple) (Object, error) {
	sMap := self.(StringDict)
	o := make([]Object, 0, len(sMap))
	for k, v := range sMap {
	o = append(o, Tuple{String(k), v})
	}
	return NewIterator(o), nil
	}, 0, "items() -> list of D's (key, value) pairs, as 2-tuples")
	}

I think we should add an error to this part of the code.

For me it works in CPython 3.7.4 as in GPython.

[Sungmin-Joo]

@Tim-St
I found a mistake in the code I used in the issue.
Please check again.

Yes, the code requires the following check at the top:

err := UnpackTuple(args, nil, "items", 0, 0)
if err != nil {
    return nil, err
}

It could even be more correct by allowing to call dict.items(someDict), like I've implemented it in list.sort.

[Sungmin-Joo]

@Tim-St
Ok.
When I finish my ongoing Pull Request, I'll do this right away.