Importerror: Cannot Import Name 'Six' from 'Django. Utils'

Recently, I upgraded the version of Django framework from 2.0.6 to 3.0 and suddenly after calling python manage.py shell command, I got this exception:

ImportError: cannot import name 'six' from 'django.utils' (/path-to-project/project/venv/lib/python3.7/site-packages/django/utils/init.py)

Full trace:

Traceback (most recent call last):
  File "manage.py", line 13, in <module>
    execute_from_command_line(sys.argv)
  File "/path-to-project/project/venv/lib/python3.7/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "/path-to-project/project/venv/lib/python3.7/site-packages/django/core/management/__init__.py", line 377, in execute
    django.setup()
  File "/path-to-project/project/venv/lib/python3.7/site-packages/django/__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/path-to-project/project/venv/lib/python3.7/site-packages/django/apps/registry.py", line 91, in populate
    app_config = AppConfig.create(entry)
  File "/path-to-project/project/venv/lib/python3.7/site-packages/django/apps/config.py", line 90, in create
    module = import_module(entry)
  File "/usr/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/path-to-project/project/venv/lib/python3.7/site-packages/corsheaders/__init__.py", line 1, in <module>
    from .checks import check_settings  # noqa: F401
  File "/path-to-project/project/venv/lib/python3.7/site-packages/corsheaders/checks.py", line 7, in <module>
    from django.utils import six

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I read this Question and this django-3.0, release note , but those resources couldn't help me.