Превышена максимальная глубина рекурсии при вызове объекта Python с помощью def __str__(self): когда я удаляю объект вст ⇐ Python

[Anonymous]

Я сталкиваюсь с ошибкой "Превышена максимальная глубина рекурсии..." при попытке удалить одну из встроенных форм в администраторе Django.
Это моя модель:
class Correction_Factors(models.Model):

Treatment_unit= models.ManyToManyField(Unit,blank=False)

def __str__(self):
return u", ".join([a.name for a in self.Treatment_unit.all()])

Похоже, проблема в self.Treatment_unit.all(). При создании встроенной формы ошибок не произошло. Он появился только тогда, когда я начал удалять одну из встроенных форм.
Я пытался переключиться на def __Unicode__(self):, но он не дал того, что я ожидал. Возвращенный текст выглядел как «Объект Correction_Factors (23)» без каких-либо подробностей.
Примечание. С def __Unicode__(self): нет проблем с удалением. И я использую Django 2.2.18 и Python 3.9.2.
введите описание изображения здесь
Environment:

Request Method: POST
Request URL: http://127.0.0.1:8000/admin/output/dosi ... 18/change/

Django Version: 2.2.18
Python Version: 3.9.2
Installed Applications:
['django.contrib.admin',
'django.contrib.contenttypes',
'django.contrib.auth',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.messages',
'django.contrib.staticfiles',
'django.contrib.humanize',
'django_extensions',
'django_q',
'django_comments',
'formtools',
'django_filters',
'rest_framework',
'rest_framework_filters',
'rest_framework.authtoken',
'listable',
'genericdropdown',
'recurrence',
'widget_tweaks',
'dynamic_raw_id',
'mptt',
'django_mptt_admin',
'qatrack.cache',
'qatrack.accounts',
'qatrack.units',
'qatrack.qa',
'qatrack.qatrack_core',
'qatrack.notifications',
'qatrack.contacts',
'qatrack.issue_tracker',
'qatrack.service_log',
'qatrack.parts',
'qatrack.faults',
'qatrack.attachments',
'qatrack.reports',
'admin_views',
'qatrack.output',
'simple_history']
Installed Middleware:
['django.middleware.common.CommonMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'qatrack.middleware.login_required.LoginRequiredMiddleware',
'qatrack.middleware.maintain_filters.FilterPersistMiddleware']

Traceback:

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\core\handlers\exception.py" in inner
34. response = get_response(request)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\core\handlers\base.py" in _get_response
115. response = self.process_exception_by_middleware(e, request)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\core\handlers\base.py" in _get_response
113. response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\contrib\admin\options.py" in wrapper
606. return self.admin_site.admin_view(view)(*args, **kwargs)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\utils\decorators.py" in _wrapped_view
142. response = view_func(request, *args, **kwargs)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\views\decorators\cache.py" in _wrapped_view_func
44. response = view_func(request, *args, **kwargs)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\contrib\admin\sites.py" in inner
223. return view(request, *args, **kwargs)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\contrib\admin\options.py" in change_view
1648. return self.changeform_view(request, object_id, form_url, extra_context)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\utils\decorators.py" in _wrapper
45. return bound_method(*args, **kwargs)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\utils\decorators.py" in _wrapped_view
142. response = view_func(request, *args, **kwargs)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\contrib\admin\options.py" in changeform_view
1529. return self._changeform_view(request, object_id, form_url, extra_context)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\contrib\admin\options.py" in _changeform_view
1574. change_message = self.construct_change_message(request, form, formsets, add)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\contrib\admin\options.py" in construct_change_message
1050. return construct_change_message(form, formsets, add)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\contrib\admin\utils.py" in construct_change_message
520. 'object': str(deleted_object),

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __get__
527. return self.related_manager_cls(instance)

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py" in __init__
838. raise ValueError('"%r" needs to have a value for field "%s" before '

File "C:\Users\mmetwaly\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py" in __repr__
519. return '' % (self.__class__.__name__, self)

File "H:\Python projects\deploy\qatrackplus\qatrack\output\models.py" in __str__
207. list_01 =self.Treatment_unit.all()


Подробнее здесь: https://stackoverflow.com/questions/664 ... th-def-str