Django NoReverseMatch not a valid view function -

django 1.11

i keep getting noreversematch error reverse 'menu_menuitem' not found. 'menu_menuitem' not valid view function or battern name

views.py

from .models import category, menuitem  def show_category(request, category_slug):     c = get_object_or_404(category, slug=category_slug)     menuitems = c.menuitem_set.all()\     template_name='category.html'     context = {     'c':c,     'menuitems':menuitems,     }     return render(request, template_name, context)  def show_menuitem(request, menuitem_slug):     = get_object_or_404(menuitem, slug=menuitem_slug)     categories = i.categories.filter(is_active=true)     template_name="menuitem.html"     context = {     'i':i,     }     return render(request, template_name, context) 

models.py

class category(models.model):    name = models.charfield(max_length=50)    slug = models.slugfield(max_length=50, unique=true,        help_text='unique value category page url, created name.', blank=true, null=true)    @models.permalink    def get_absolute_url(self):        return ('menu_category', (), { 'category_slug': self.slug })     class menuitem(models.model):     name = models.charfield(max_length=250, blank=false, unique=true)     slug = models.slugfield(max_length=250, unique=true,         help_text='unique value menuitem page url, created name.', blank=true, null=true)     categories = models.manytomanyfield(category)      @models.permalink     def get_absolute_url(self):         return ('menu_menuitem', (), { 'menuitem_slug': self.slug }) 

for category model

@models.permalink    def get_absolute_url(self):        return ('show_category', (), { 'category_slug': self.slug }) 

for menuitemmodel

@models.permalink     def get_absolute_url(self):         return ('show_menuitem', (), { 'menuitem_slug': self.slug })