'generator' object has no attribute '__dict__

[Gigme18]

When I am calling GroupkFold.split()
Internally it is calling python bridge

I am getting an error in python bridge:

error: undefined,
exception: {
type: { name: 'AttributeError', module: 'builtins' },
message: "'generator' object has no attribute 'dict'",
args: [ "'generator' object has no attribute 'dict'" ],
format: [
"AttributeError: 'generator' object has no attribute 'dict'\n"
]

traceback: {
lineno: 111,
strack: [
' File "node_modules@fisch0920\python-bridge\node_python_bridge.py", line 114, in \n' +
" response = dict(type='exception', value=format_exception(t, e, tb))\n"
],
format: [
' File "..\node_modules@fisch0920\python-bridge\node_python_bridge.py", line 111, in \n' +
" response = dict(type='success', value=json.dumps(value, separators=(',', ':'), cls=JavaScriptEncoder))\n",
' File "Programs\Python\Python310\lib\json\init.py", line 238, in dumps\n' +
' **kw).encode(obj)\n',
' File "Programs\Python\Python310\lib\json\encoder.py", line 199, in encode\n' +
' chunks = self.iterencode(o, _one_shot=True)\n',
' File "Python\Python310\lib\json\encoder.py", line 257, in iterencode\n'
+
' return _iterencode(o, 0)\n',
' File "node_modules@fisch0920\python-bridge\node_python_bridge.py", line 81, in default\n' +
' return o.dict\n'
]
},

I am confused why this error is triggered.