KeyError: None

[Murtrag]

2021-10-06 08:13:55,065: Internal Server Error: /admin/resume/sectioncontent/
Traceback (most recent call last):
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/core/handlers/base.py", line 179, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/contrib/admin/options.py", line 614, in wrapper
    return self.admin_site.admin_view(view)(*args, **kwargs)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/utils/decorators.py", line 130, in _wrapped_view
    response = view_func(request, *args, **kwargs)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/views/decorators/cache.py", line 44, in _wrapped_view_func
    response = view_func(request, *args, **kwargs)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/contrib/admin/sites.py", line 233, in inner
    return view(request, *args, **kwargs)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/utils/decorators.py", line 43, in _wrapper
    return bound_method(*args, **kwargs)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/utils/decorators.py", line 130, in _wrapped_view
    response = view_func(request, *args, **kwargs)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/contrib/admin/options.py", line 1693, in changelist_view
    cl = self.get_changelist_instance(request)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/contrib/admin/options.py", line 748, in get_changelist_instance
    sortable_by,
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/contrib/admin/views/main.py", line 99, in __init__
    self.queryset = self.get_queryset(request)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/contrib/admin/views/main.py", line 450, in get_queryset
    ) = self.get_filters(request)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/contrib/admin/views/main.py", line 137, in get_filters
    spec = list_filter(request, lookup_params, self.model, self.model_admin)
  File "/home/Murtrag/.virtualenvs/resume-virtualenv/lib/python3.7/site-packages/django/contrib/admin/filters.py", line 76, in __init__
    lookup_choices = self.lookups(request, model_admin)
  File "/home/Murtrag/AutoResume/resume/admin.py", line 50, in lookups
    formated = [(x[2], (f'{x[0]} - {LanguageDict[x[1]]}')) for x in list]
  File "/home/Murtrag/AutoResume/resume/admin.py", line 50, in <listcomp>
    formated = [(x[2], (f'{x[0]} - {LanguageDict[x[1]]}')) for x in list]
KeyError: None

Happend when user have None value as language, then this line
formated = [(x[2], (f'{x[0]} - {LanguageDict[x[1]]}')) for x in list]
throws an error because LanguageDict doasn't have None key