self._sections = self._dict()
self._defaults = self._dict()
if allow_no_value:
    self._optcre = self.OPTCRE_NV
else:
    self._optcre = self.OPTCRE
if defaults:
    for key, value in list(defaults.items()):
        self._defaults[self.optionxform(key)] = value
Python configparser will not accept keys without values