Previous custom dict_type yields an error on python 3.6 and up

[Yarboa]

class M(dict):
    def __setitem__(self, key, value):
        if len(value) > 1:
            return
        if key in self:
            items = self[key]
            new = value[0] if type(value) is list else value
            if new not in items:
                items.append(new)
        else:
            super().__setitem__(key, value)

config_parser_args
{'allow_no_value': True, 'strict': False, 'dict_type': <class 'main.main..M'>}
get_value = ConfigParser(**config_parser_args)

Raising the following Error:
AttributeError: 'ConfigParser' object has no attribute 'default_section'
Uncaught exception. Entering post mortem debugging
Running 'cont' or 'step' will restart the program

/home/yrachman/os-client/tmp/python-test/venv-3.6/lib/python3.6/site-packages/backports/configparser/init.py(1383)_options()
-> if self._name != self._parser.default_section:

python -V Python 3.6.8
configparser 5.0.0

Removing dict_type, works well

Had the following code working till python3.5 w/ configparser 4.0.2

[Yarboa]

Closing this,
Override of OrderedDict solved it

    class M(OrderedDict):
        def __setitem__(self, key, value):
            print("key", key, " value:" ,value, end=" ")  
            v_val = self.get(key)
            if v_val is not None and type(value)==list:
               v_val.append(value[0])
            else:
               v_val = value
            super().__setitem__(key, v_val)