Why I am getting "Not Implemented Error: Database objects do not implement truth value testing or bool()." while running makemigration cmd in django

Question

I am trying to connect Django with MongoDB using Djongo. I have changed the Database parameter but I am getting this error Not Implemented Error: Database objects do not implement truth value testing or bool(). when I am running makemigration command.

Please can anybody explain why I am getting this error and how to resolve it?

I have include settings.py file, error log and mongodb compass setup image.

settings.py

"""
Django settings for Chatify project.

Generated by 'django-admin startproject' using Django 3.2.9.

For more information on this file, see
https://docs.djangoproject.com/en/3.2/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/3.2/ref/settings/
"""

from pathlib import Path

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.2/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'django-insecure-1k4mo05el_0112guspx^004n-i&3h#u4gyev#27u)tkb8t82_%'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'api.apps.ApiConfig',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'Chatify.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'Chatify.wsgi.application'


# Database
# https://docs.djangoproject.com/en/3.2/ref/settings/#databases

# DATABASES = {
#     'default': {
#         'ENGINE': 'django.db.backends.sqlite3',
#         'NAME': BASE_DIR / 'db.sqlite3',
#     }
# }
DATABASES = {
       'default': {
           'ENGINE': 'djongo',
           'NAME': 'users',
       }
}


# Password validation
# https://docs.djangoproject.com/en/3.2/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/3.2/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.2/howto/static-files/

STATIC_URL = '/static/'

# Default primary key field type
# https://docs.djangoproject.com/en/3.2/ref/settings/#default-auto-field

DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'

Error Log

File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "C:\Users\DELL\AppData\Local\Programs\Python\Python37\lib\site-packages\django\core\management\__init__.py", line 419, in execute_from_command_line
    utility.execute()
  File "C:\Users\DELL\AppData\Local\Programs\Python\Python37\lib\site-packages\django\core\management\__init__.py", line 413, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Users\DELL\AppData\Local\Programs\Python\Python37\lib\site-packages\django\core\management\base.py", line 367, in run_from_argv
    connections.close_all()
  File "C:\Users\DELL\AppData\Local\Programs\Python\Python37\lib\site-packages\django\db\utils.py", line 213, in close_all
    connection.close()
  File "C:\Users\DELL\AppData\Local\Programs\Python\Python37\lib\site-packages\django\utils\asyncio.py", line 33, in inner
    return func(*args, **kwargs)
  File "C:\Users\DELL\AppData\Local\Programs\Python\Python37\lib\site-packages\django\db\backends\base\base.py", line 294, in close
    self._close()
  File "C:\Users\DELL\AppData\Local\Programs\Python\Python37\lib\site-packages\djongo\base.py", line 208, in _close
    if self.connection:
  File "C:\Users\DELL\AppData\Local\Programs\Python\Python37\lib\site-packages\pymongo\database.py", line 829, in __bool__
    raise NotImplementedError("Database objects do not implement truth "
NotImplementedError: Database objects do not implement truth value testing or bool(). Please compare with None instead: database is not None

MongoDBCompass MongoDB Local Database Image

Answer 1

The problem is with the new version of pymongo (4.0 from 29.11.2021) which is not supported by Djongo 1.3.6. You need to install pymongo 3.12.1. I had the same problem 2 hours ago.

Answer 2

The actual problem is with pymongo==4.0.1. when installing the mongoengine by pip install mongoengine it installs the pymongo==3.12.3 So, it is not necessary to again install mongoengine just install pymongo==3.12.3 by pip install pymongo==3.12.3.