Post 오류창

A server error occurred.  Please contact the administrator.

def __str__(self):
    return '{} :: {}'.format(self, self.title, self.author)


이 줄들을 입력하고 cmder 열어서 python manage.py runserver 한 뒤,
창을 열고 Post 를 열어보면

흰 바탕화면에 A server error occurred.  Please contact the administrator. 달랑 이 문구만 나옵니다....

그리고 cmder을 확인해보면

C:\github\django_my_website (master -> origin)
(venv) λ python manage.py runserver
Watching for file changes with StatReloader
Performing system checks...

System check identified no issues (0 silenced).
March 19, 2020 - 15:01:28
Django version 2.2, using settings 'my_site_prj.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CTRL-BREAK.
[19/Mar/2020 15:01:30] "GET /admin/blog/ HTTP/1.1" 200 2410
Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\db\models\options.py", line 565, in get_field
    return self.fields_map[field_name]
KeyError: '__str__'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\contrib\admin\utils.py", line 262, in lookup_field
    f = _get_non_gfk_field(opts, name)
  File "C:\github\django_my_website\venv\lib\site-packages\django\contrib\admin\utils.py", line 293, in _get_non_gfk_field
    field = opts.get_field(name)
  File "C:\github\django_my_website\venv\lib\site-packages\django\db\models\options.py", line 567, in get_field
    raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, field_name))
django.core.exceptions.FieldDoesNotExist: Post has no field named '__str__'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\base.py", line 145, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\base.py", line 143, in _get_response
    response = response.render()
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\response.py", line 106, in render
    self.content = self.rendered_content
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\response.py", line 83, in rendered_content
    content = template.render(context, self._request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\backends\django.py", line 61, in render
    return self.template.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 171, in render
    return self._render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 163, in _render
    return self.nodelist.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 937, in render
    bit = node.render_annotated(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 904, in render_annotated
    return self.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\loader_tags.py", line 150, in render
    return compiled_parent._render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 163, in _render
    return self.nodelist.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 937, in render
    bit = node.render_annotated(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 904, in render_annotated
    return self.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\loader_tags.py", line 150, in render
    return compiled_parent._render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 163, in _render
    return self.nodelist.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 937, in render
    bit = node.render_annotated(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 904, in render_annotated
    return self.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 937, in render
    bit = node.render_annotated(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 904, in render_annotated
    return self.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 937, in render
    bit = node.render_annotated(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\base.py", line 904, in render_annotated
    return self.render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\contrib\admin\templatetags\base.py", line 33, in render
    return super().render(context)
  File "C:\github\django_my_website\venv\lib\site-packages\django\template\library.py", line 214, in render
    _dict = self.func(*resolved_args, **resolved_kwargs)
  File "C:\github\django_my_website\venv\lib\site-packages\django\contrib\admin\templatetags\admin_list.py", line 339, in result_list
    'results': list(results(cl)),
  File "C:\github\django_my_website\venv\lib\site-packages\django\contrib\admin\templatetags\admin_list.py", line 315, in results
    yield ResultList(None, items_for_result(cl, res, None))
  File "C:\github\django_my_website\venv\lib\site-packages\django\contrib\admin\templatetags\admin_list.py", line 306, in __init__
    super().__init__(*items)
  File "C:\github\django_my_website\venv\lib\site-packages\django\contrib\admin\templatetags\admin_list.py", line 229, in items_for_result
    f, attr, value = lookup_field(field_name, result, cl.model_admin)
  File "C:\github\django_my_website\venv\lib\site-packages\django\contrib\admin\utils.py", line 275, in lookup_field
    value = attr()
  File "C:\github\django_my_website\blog\models.py", line 14, in __str__
    return '{} :: {}'.format(self, self.title, self.author)
  File "C:\github\django_my_website\blog\models.py", line 14, in __str__
    return '{} :: {}'.format(self, self.title, self.author)
  File "C:\github\django_my_website\blog\models.py", line 14, in __str__
    return '{} :: {}'.format(self, self.title, self.author)
  [Previous line repeated 230 more times]
RecursionError: maximum recursion depth exceeded

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\utils\deprecation.py", line 94, in __call__
    response = response or self.get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 36, in inner
    response = response_for_exception(request, exc)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 90, in response_for_exception
    response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info())
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 125, in handle_uncaught_exception
    return debug.technical_500_response(request, *exc_info)
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 94, in technical_500_response
    html = reporter.get_traceback_html()
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 332, in get_traceback_html
    t = DEBUG_ENGINE.from_string(fh.read())
UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 9735: illegal multibyte sequence

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\utils\deprecation.py", line 94, in __call__
    response = response or self.get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 36, in inner
    response = response_for_exception(request, exc)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 90, in response_for_exception
    response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info())
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 125, in handle_uncaught_exception
    return debug.technical_500_response(request, *exc_info)
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 94, in technical_500_response
    html = reporter.get_traceback_html()
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 332, in get_traceback_html
    t = DEBUG_ENGINE.from_string(fh.read())
UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 9735: illegal multibyte sequence

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\utils\deprecation.py", line 94, in __call__
    response = response or self.get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 36, in inner
    response = response_for_exception(request, exc)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 90, in response_for_exception
    response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info())
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 125, in handle_uncaught_exception
    return debug.technical_500_response(request, *exc_info)
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 94, in technical_500_response
    html = reporter.get_traceback_html()
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 332, in get_traceback_html
    t = DEBUG_ENGINE.from_string(fh.read())
UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 9735: illegal multibyte sequence

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\utils\deprecation.py", line 94, in __call__
    response = response or self.get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 36, in inner
    response = response_for_exception(request, exc)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 90, in response_for_exception
    response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info())
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 125, in handle_uncaught_exception
    return debug.technical_500_response(request, *exc_info)
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 94, in technical_500_response
    html = reporter.get_traceback_html()
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 332, in get_traceback_html
    t = DEBUG_ENGINE.from_string(fh.read())
UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 9735: illegal multibyte sequence

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\utils\deprecation.py", line 94, in __call__
    response = response or self.get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 36, in inner
    response = response_for_exception(request, exc)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 90, in response_for_exception
    response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info())
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 125, in handle_uncaught_exception
    return debug.technical_500_response(request, *exc_info)
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 94, in technical_500_response
    html = reporter.get_traceback_html()
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 332, in get_traceback_html
    t = DEBUG_ENGINE.from_string(fh.read())
UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 9735: illegal multibyte sequence

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\utils\deprecation.py", line 94, in __call__
    response = response or self.get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 36, in inner
    response = response_for_exception(request, exc)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 90, in response_for_exception
    response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info())
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 125, in handle_uncaught_exception
    return debug.technical_500_response(request, *exc_info)
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 94, in technical_500_response
    html = reporter.get_traceback_html()
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 332, in get_traceback_html
    t = DEBUG_ENGINE.from_string(fh.read())
UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 9735: illegal multibyte sequence

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\utils\deprecation.py", line 94, in __call__
    response = response or self.get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 36, in inner
    response = response_for_exception(request, exc)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 90, in response_for_exception
    response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info())
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 125, in handle_uncaught_exception
    return debug.technical_500_response(request, *exc_info)
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 94, in technical_500_response
    html = reporter.get_traceback_html()
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 332, in get_traceback_html
    t = DEBUG_ENGINE.from_string(fh.read())
UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 9735: illegal multibyte sequence

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\Lee Ji Hyun\anaconda3\lib\wsgiref\handlers.py", line 137, in run
    self.result = application(self.environ, self.start_response)
  File "C:\github\django_my_website\venv\lib\site-packages\django\contrib\staticfiles\handlers.py", line 65, in __call__
    return self.application(environ, start_response)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\wsgi.py", line 141, in __call__
    response = self.get_response(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\base.py", line 75, in get_response
    response = self._middleware_chain(request)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 36, in inner
    response = response_for_exception(request, exc)
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 90, in response_for_exception
    response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info())
  File "C:\github\django_my_website\venv\lib\site-packages\django\core\handlers\exception.py", line 125, in handle_uncaught_exception
    return debug.technical_500_response(request, *exc_info)
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 94, in technical_500_response
    html = reporter.get_traceback_html()
  File "C:\github\django_my_website\venv\lib\site-packages\django\views\debug.py", line 332, in get_traceback_html
    t = DEBUG_ENGINE.from_string(fh.read())
UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 9735: illegal multibyte sequence
[19/Mar/2020 15:01:33] "GET /admin/blog/post/ HTTP/1.1" 500 59




너무 길어서 멘붕이 되는데 무슨 소린지 모르겠어서 끝 줄 오류부분 UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 9735: illegal multibyte sequence 이것만 검색해서 찾아봤더니
debug.py 에서 비어있던 open method에서 encoding = "utf-8" 도 기입했고 span 은 고칠게 따로 없었고 그랬습니다..

뭐가 잘못된 것일까요,,,

ㅕ