code: def render_category(category='', template=None):
      
      # pylint:disable=too-many-return-statements
  
      # See if this is an aliased path
      redir = get_redirect()
      if redir:
          return redir
  
      # Forbidden template types
      if template and template.startswith('_'):
          raise http_error.Forbidden("Template is private")
      if template in ['entry', 'error']:
          raise http_error.BadRequest("Invalid view requested")
  
      if category:
          # See if there's any entries for the view...
          if not orm.select(e for e in model.Entry if e.category == category or
                            e.category.startswith(category + '/')):
              raise http_error.NotFound("No such category")
  
      if not template:
          template = Category(category).get('Index-Template') or 'index'
  
      tmpl = map_template(category, template)
  
      if not tmpl:
          # this might actually be a malformed category URL
          test_path = '/'.join((category, template)) if category else template
          logger.debug("Checking for malformed category %s", test_path)
          record = orm.select(
              e for e in model.Entry if e.category == test_path).exists()
          if record:
              return redirect(url_for('category', category=test_path, **request.args))
  
          # nope, we just don't know what this is
          raise http_error.NotFound("No such view")
  
      view_spec = view.parse_view_spec(request.args)
      view_spec['category'] = category
      view_obj = view.View(view_spec)
  
      rendered, etag = render_publ_template(
          tmpl,
          _url_root=request.url_root,
          category=Category(category),
          view=view_obj)
  
      if request.if_none_match.contains(etag):
          return 'Not modified', 304
  
      return rendered, {'Content-Type': mime_type(tmpl),
                        'ETag': etag}
docs: Render a category page.
  
      Arguments:
  
      category -- The category to render
      template -- The template to render it with