The problem implementing print in gpython.

[Sungmin-Joo]

Even if sep is not required, the option must be inserted.

gpython

with open("testfile","w") as f:
    print("1234", end = "@@@", file = f)
with open("testfile","r") as f:
    print(f.read())`

Traceback (most recent call last):
  File "test.py", line 3, in <module>
    FIXME line of source goes here
TypeError: 'print() argument 2 must be str, not file'
2019/09/26 11:21:21 TypeError: 'print() argument 2 must be str, not file'

when fixed code

with open("testfile","w") as f:
    print("1234", sep = '', end = "@@@", file = f)
with open("testfile","r") as f:
    print(f.read())

1234@@@

[ncw]

The gpython print is fairly minimal at the moment and certainly needs improving.

I think this particular bug is caused by this line doing the argument parsing wrong (not sure exactly why).

gpython/builtin/builtin.go

Line 185 in 4b347aa

err := py.ParseTupleAndKeywords(nil, kwargs, "|ssOO:print", kwlist, &sepObj, &endObj, &file, &flush)

[Sungmin-Joo]

@ncw
There is a temporary way to modify the builtin_print.
But I don't think it's the right way.

func builtin_print(self py.Object, args py.Tuple, kwargs py.StringDict) (py.Object, error) {
    var (
        sepObj py.Object = py.String(" ")
        endObj py.Object = py.String("\n")
        file   py.Object = py.MustGetModule("sys").Globals["stdout"]
        flush  py.Object
    )
    kwlist := []string{"sep", "end", "file", "flush"}
    for _, kw := range kwlist {
        switch _, ok := kwargs[kw]; ok {
        case true:
            continue
        default:
            if kw == "sep" {
                kwargs[kw] = sepObj
            } else if kw == "end" {
                kwargs[kw] = endObj
            } else if kw == "file" {
                kwargs[kw] = file
            } else {
                kwargs[kw] = flush
            }
        }
    }
    err := py.ParseTupleAndKeywords(nil, kwargs, "|ssOO:print", kwlist, &sepObj, &endObj, &file, &flush)
    ...

[ncw]

py.ParseTupleAndKeywords should be doing that for us...

The bug must be in this bit of code I think... No time to investigate further right now - over to you to have a look!

gpython/py/args.go

Lines 444 to 453 in 8c361a8

	for i, kw := range kwlist {
	if value, ok := kwargs[kw]; ok {
	if len(args) > i {
	return ExceptionNewf(TypeError, "%s() got multiple values for argument '%s'", name, kw)
	}
	args = append(args, value)
	} else if keywordOnly {
	args = append(args, nil)
	}
	}

[drew-512]

suggest @sbinet close -- fixed w/ #151

[sbinet]

fixed w/ #151.