              pass
          else:
              # Check if this is a REST framework view, and if so add it to the breadcrumbs
              if isinstance(getattr(view, 'cls_instance', None), APIView):
                  breadcrumbs_list.insert(0, (view.cls_instance.get_name(), prefix + url))
  
          if url == '':
              # All done
              return breadcrumbs_list
  
 
</s> remove             return breadcrumbs_recursive(url.rstrip('/'), breadcrumbs_list, prefix)
 </s> add             return breadcrumbs_recursive(url.rstrip('/'), breadcrumbs_list, prefix, seen) </s> remove         return breadcrumbs_recursive(url[:url.rfind('/') + 1], breadcrumbs_list, prefix)
 </s> add         return breadcrumbs_recursive(url[:url.rfind('/') + 1], breadcrumbs_list, prefix, seen) </s> remove     def breadcrumbs_recursive(url, breadcrumbs_list, prefix):
 </s> add     def breadcrumbs_recursive(url, breadcrumbs_list, prefix, seen): </s> remove     return breadcrumbs_recursive(url, [], prefix)
 </s> add     return breadcrumbs_recursive(url, [], prefix, [])
                # Don't list the same view twice in a row.
                # Probably an optional trailing slash.
                if not seen or seen[-1] != view:
                    breadcrumbs_list.insert(0, (view.cls_instance.get_name(), prefix + url))
                    seen.append(view)
              pass
          else:
              # Check if this is a REST framework view, and if so add it to the breadcrumbs
              if isinstance(getattr(view, 'cls_instance', None), APIView):
                # Don't list the same view twice in a row.
                # Probably an optional trailing slash.
                if not seen or seen[-1] != view:
                    breadcrumbs_list.insert(0, (view.cls_instance.get_name(), prefix + url))
                    seen.append(view)
  
          if url == '':
              # All done
              return breadcrumbs_list
  
keep keep keep keep replace keep keep keep keep keep
 Fix repeated breadcrumbs when optional trailing slash is used 
rest_framework/utils/breadcrumbs.py