title: URL passes parameter in my Django project
body: <p>I am just a beginner of Django, these days I followed a mooc to learn Django, I wanted to set up my first website, but something went wrong and I can not figure out. I wanted to write a regex with parameter 'cate' in URLS.py to match the video function in my view.py, judging whether 'cate' eequals 'editors', if yes it will bring back data with attribute "editors_choice". However, I found no it never changes, so I printed 'cate' in view.py and found it always None and I still don't know why.</p>
  
  <p>Following is my code:</p>
  
  <pre><code>def video(request, cate=None):
      print(cate)
      context = {} =
      if cate is None:
          video_list = Video.objects.all()
      if cate == 'editors':
          video_list = Video.objects.filter(editors_choices=True)
      else:
          video_list = Video.objects.all()
      page_robot = Paginator(video_list, 16)
      page_num = request.GET.get('page')
      try:
          video_list = page_robot.page(page_num)
      except EmptyPage:
          video_list = page_robot.page(page_robot.num_pages)  # raise HTTP404("Empty")
      except PageNotAnInteger:
          video_list = page_robot.page(1)
      context['video_list'] = video_list
      return render(request, 'ten_movie.html', context)
  </code></pre>
  
  <hr>
  
  <p><img src="https://i.stack.imgur.com/CCTLo.png" alt="&#39;cate&#39; parameter in urls.py"></p>
  
  <hr>
  
  <p><img src="https://i.stack.imgur.com/mjOT3.png" alt="templete"></p>