TechQA.

AttributeError: model object has no attribute 'rel'

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In django 1.9 I used this custom MultilingualCharField, then I upgrade to django 2.0 and it give error at runserver:

class MultilingualCharField(models.CharField):

    def __init__(self, verbose_name=None, **kwargs):
        self._blank = kwargs.get("blank", False)
        self._editable = kwargs.get("editable", True)
        #super(MultilingualCharField, self).__init__(verbose_name, **kwargs)
        super().__init__(verbose_name, **kwargs)

    def contribute_to_class(self, cls, name, virtual_only=False):
        # generate language specific fields dynamically
        if not cls._meta.abstract:
            for lang_code, lang_name in settings.LANGUAGES:
                if lang_code == settings.LANGUAGE_CODE:
                    _blank = self._blank
                else:
                    _blank = True
                localized_field = models.CharField(string_concat(
                    self.verbose_name, " (%s)" % lang_code),
                    name=self.name,
                    primary_key=self.primary_key,
                    max_length=self.max_length,
                    unique=self.unique,
                    blank=_blank,
                    null=False,
                    # we ignore the null argument!
                    db_index=self.db_index,
                    rel=self.rel,
                    default=self.default or "",
                    editable=self._editable,
                    serialize=self.serialize,
                    choices=self.choices,
                    help_text=self.help_text,
                    db_column=None,
                    db_tablespace=self.db_tablespace
                )
                localized_field.contribute_to_class(cls, 
                    "%s_%s" % (name, lang_code),)

        def translated_value(self):
            language = get_language()
            val = self.__dict__["%s_%s" % (name, language)]
            if not val:
                val = self.__dict__["%s_%s" % (name, settings.LANGUAGE_CODE)]
                return val

        setattr(cls, name, property(translated_value))

    def name(self):
        name_translated='name'+settings.LANGUAGE_CODE
        return name_translated

Here's the error:

(possedimenti) D:\Python\progetti\possedimenti\sitopossedimenti>manage.py runserver
Unhandled exception in thread started by <function check_errors.<locals>.wrapper
 at 0x03BCB8E8>
Traceback (most recent call last):
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\utils\autoreload.py
", line 225, in wrapper
    fn(*args, **kwargs)
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\core\management\com
mands\runserver.py", line 112, in inner_run
    autoreload.raise_last_exception()
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\utils\autoreload.py
", line 248, in raise_last_exception
    raise _exception[1]
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\core\management\__i
nit__.py", line 327, in execute
    autoreload.check_errors(django.setup)()
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\utils\autoreload.py
", line 225, in wrapper
    fn(*args, **kwargs)
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\__init__.py", line
24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\apps\registry.py",
line 112, in populate
    app_config.import_models()
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\apps\config.py", li
ne 198, in import_models
    self.models_module = import_module(models_module_name)
  File "D:\python\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "D:\Python\progetti\possedimenti\sitopossedimenti\core\models\__init__.py
", line 1, in <module>
    from core.models.campaign import Source, Ability
  File "D:\Python\progetti\possedimenti\sitopossedimenti\core\models\campaign.py
", line 6, in <module>
    class Ability(models.Model):
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\db\models\base.py",
 line 152, in __new__
    new_class.add_to_class(obj_name, obj)
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\db\models\base.py",
 line 315, in add_to_class
    value.contribute_to_class(cls, name)
  File "D:\Python\progetti\possedimenti\sitopossedimenti\sitopossedimenti\utils.
py", line 45, in contribute_to_class
    rel=self.rel,
AttributeError: 'MultilingualCharField' object has no attribute 'rel'

Maybe in django 2.0 that attribute don't exist anymore? I don't know what it is and what I need for. thank you for your help. If I comment out that line it looks like is working... but I'm not sure what it will do in future...

Edit:

So, it is deprecated (also here), anyone know what I should do? I tried to change the line in contribute_to_class (see above) in:

...
#rel=self.rel,
remote_field=self.remote_field,
...

but it gives an error in .../models/__init__.py:

TypeError: __init__() got an unexpected keyword argument 'remote_field'

complete traceback:

Unhandled exception in thread started by <function check_errors.<locals>.wrapper
 at 0x03BF0108>
Traceback (most recent call last):
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\utils\autoreload.py
", line 225, in wrapper
    fn(*args, **kwargs)
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\core\management\com
mands\runserver.py", line 112, in inner_run
    autoreload.raise_last_exception()
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\utils\autoreload.py
", line 248, in raise_last_exception
    raise _exception[1]
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\core\management\__i
nit__.py", line 327, in execute
    autoreload.check_errors(django.setup)()
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\utils\autoreload.py
", line 225, in wrapper
    fn(*args, **kwargs)
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\__init__.py", line
24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\apps\registry.py",
line 112, in populate
    app_config.import_models()
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\apps\config.py", li
ne 198, in import_models
    self.models_module = import_module(models_module_name)
  File "D:\python\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "D:\Python\progetti\possedimenti\sitopossedimenti\core\models\__init__.py
", line 1, in <module>
    from core.models.campaign import Source, Ability
  File "D:\Python\progetti\possedimenti\sitopossedimenti\core\models\campaign.py
", line 6, in <module>
    class Ability(models.Model):
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\db\models\base.py",
 line 152, in __new__
    new_class.add_to_class(obj_name, obj)
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\db\models\base.py",
 line 315, in add_to_class
    value.contribute_to_class(cls, name)
  File "D:\Python\progetti\possedimenti\sitopossedimenti\sitopossedimenti\utils.
py", line 53, in contribute_to_class
    db_tablespace=self.db_tablespace
  File "D:\Python\Envs\possedimenti\lib\site-packages\django\db\models\fields\__
init__.py", line 1042, in __init__
    super().__init__(*args, **kwargs)
TypeError: __init__() got an unexpected keyword argument 'remote_field'
django-models attributes deprecated django-2.0 django-upgrade
Original Q&A
1

There are 1 answers

8
Oliver Falk On BEST ANSWER

I'm eventually experiencing a similar or related issue:

File "XXX/.virtualenv/lib/python3.4/site-packages/natural_keys/models.py", line 168, in natural_key
  for name in self.get_natural_key_fields()]
File "XXX/.virtualenv/lib/python3.4/site-packages/natural_keys/models.py", line 149, in get_natural_key_fields
  for name, rel_to in cls.get_natural_key_info():
File "XXX/.virtualenv/lib/python3.4/site-packages/natural_keys/models.py", line 129, in get_natural_key_info
  rel_to = field.rel.to if field.rel else None
AttributeError: 'CharField' object has no attribute 'rel'

Not sure if this helps to hunt down the issue.

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