title: Exception in thread django-main-thread
body: <p>I was implementing google login by using oauth2client library and did some change in <code>/google-login/myvenv/lib/python3.5/site-packages/oauth2client/contrib/django_util/__init__.py</code>
  just replaced <code>from django.core import urlresolvers</code> to <code>from django.urls import reverse</code> and Line 411 <code>urlresolvers.reverse(...)</code> to <code>reverse(...)</code>
  While running my server
  python manage.py runserver
  A typeError occured
  Trace back of this error is:</p>
  
  <pre><code>Watching for file changes with StatReloader
  Exception in thread django-main-thread:
  Traceback (most recent call last):
    File "/usr/lib/python3.6/threading.py", line 916, in _bootstrap_inner
      self.run()
    File "/usr/lib/python3.6/threading.py", line 864, in run
      self._target(*self._args, **self._kwargs)
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/django/utils/autoreload.py", line 54, in wrapper
      fn(*args, **kwargs)
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/django/core/management/commands/runserver.py", line 109, in inner_run
      autoreload.raise_last_exception()
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/django/utils/autoreload.py", line 77, in raise_last_exception
      raise _exception[0](_exception[1]).with_traceback(_exception[2])
  TypeError: __init__() missing 2 required positional arguments: 'doc' and 'pos'
  </code></pre>
  
  <p>Got this traceback
  I have no clue what does it mean.</p>
  
  <pre><code>Traceback (most recent call last):
    File "manage.py", line 21, in &lt;module&gt;
      main()
    File "manage.py", line 17, in main
      execute_from_command_line(sys.argv)
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
      utility.execute()
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/django/core/management/__init__.py", line 357, in execute
      django.setup()
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/django/__init__.py", line 24, in setup
      apps.populate(settings.INSTALLED_APPS)
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/django/apps/registry.py", line 114, in populate
      app_config.import_models()
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/django/apps/config.py", line 211, in import_models
      self.models_module = import_module(models_module_name)
    File "/usr/lib/python3.6/importlib/__init__.py", line 126, in import_module
      return _bootstrap._gcd_import(name[level:], package, level)
    File "&lt;frozen importlib._bootstrap&gt;", line 994, in _gcd_import
    File "&lt;frozen importlib._bootstrap&gt;", line 971, in _find_and_load
    File "&lt;frozen importlib._bootstrap&gt;", line 955, in _find_and_load_unlocked
    File "&lt;frozen importlib._bootstrap&gt;", line 665, in _load_unlocked
    File "&lt;frozen importlib._bootstrap_external&gt;", line 678, in exec_module
    File "&lt;frozen importlib._bootstrap&gt;", line 219, in _call_with_frames_removed
    File "/home/akshay/django/google_login/login/models.py", line 3, in &lt;module&gt;
      from oauth2client.contrib.django_util.models import CredentialsField
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/oauth2client/contrib/django_util/__init__.py", line 365, in &lt;module&gt;
      oauth2_settings = OAuth2Settings(django.conf.settings)
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/oauth2client/contrib/django_util/__init__.py", line 341, in __init__
      info = _get_oauth2_client_id_and_secret(settings_instance)
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/oauth2client/contrib/django_util/__init__.py", line 277, in _get_oauth2_client_id_and_secret
      return _load_client_secrets(secret_json)
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/oauth2client/contrib/django_util/__init__.py", line 255, in _load_client_secrets
      client_type, client_info = clientsecrets.loadfile(filename)
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/oauth2client/clientsecrets.py", line 165, in loadfile
      return _loadfile(filename)
    File "/home/akshay/django/google_login/myvenv/lib/python3.6/site-packages/oauth2client/clientsecrets.py", line 122, in _loadfile
      obj = json.load(fp)
    File "/usr/lib/python3.6/json/__init__.py", line 299, in load
      parse_constant=parse_constant, object_pairs_hook=object_pairs_hook, **kw)
    File "/usr/lib/python3.6/json/__init__.py", line 354, in loads
      return _default_decoder.decode(s)
    File "/usr/lib/python3.6/json/decoder.py", line 339, in decode
      obj, end = self.raw_decode(s, idx=_w(s, 0).end())
    File "/usr/lib/python3.6/json/decoder.py", line 355, in raw_decode
      obj, end = self.scan_once(s, idx)
  json.decoder.JSONDecodeError: Invalid control character at: line 1 column 451 (char 450)
  </code></pre>