找不到/ students / classes / Reverse上的NoReverseMatch，以找到带有参数'（'，）'的'editclasses'

Question

我正在尝试在我的班级模型中编辑班级，但是其给出的错误帮助我尝试解决此错误

找不到带有参数'（''，）'的'editclasses'。尝试了1种模式：['学生/编辑类/（？P [0-9] +）/ $']

classes.html

{% for clas in clas %}
<tr>
  <td>{{clas.class_name}}</td>
  <td>
    <a href="{% url 'editclasses' clas.pk %}" class="btn btn-outline-info btn-sm" role="button"> Edit</a>

</td>
</tr>
{% endfor %}   

editclasses.html

div class="container">
    <h4 class="text-center">Edit Class</h4>
    <hr/> 
    <form method="POST" enctype="multipart/form-data">
        {% csrf_token %}
        {% for field in form %}
        <div class="form-group row">
            <label for="id_{{ field.name }}" class="col-2 col-form-label">{{ field.label }}</label>
            <div class="col-10">
                {{ field }}
                {{ field.errors }}
            </div>
        </div>
        {% endfor %}
        <button type="submit" class="btn btn-primary" name="button">Update</button>
    </form>
 <br/><br/>
</div>  

课程的views.py

def editclasses(request, pk):
clas = get_object_or_404(Classes, pk=pk)

if request.method == "POST":
    form = ClassesForm(request.POST or None, instance=clas)
    if form.is_valid():
        form.save()
        return redirect('home')
else:
    form = ClassesForm(instance=gr)

    return render(request, 'students/editclasses.html', {'form': form})

def classes(request):
clas = Classes.objects.all()
context = {'clas': clas}
return render(request, 'students/classes.html', context)

urls.py用于编辑类

 path('editclasses/<int:pk>/', views.editclasses, name='editclasses'),