跟老齐学Python Django实战 5/n Second edition

Traceback:

File "/home/cor/laoqidjango/lqdjango0601/lib/python3.5/site-packages/django/core/handlers/exception.py" in inner
  34.             response = get_response(request)

File "/home/cor/laoqidjango/lqdjango0601/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response
  115.                 response = self.process_exception_by_middleware(e, request)

File "/home/cor/laoqidjango/lqdjango0601/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response
  113.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/home/cor/laoqidjango/lqdjango0602/mysite2/account/views.py" in user_login
  13.             user = authenticate(username=cd['username'], password=cd['password'])

Exception Type: KeyError at /account/login/
Exception Value: 'username'