Reverse (): object "NoneType" cannot be called

I had a strange problem, at least for python / django noob is strange;)

django.core.urlresolvers.reverse () raises the NoneType object cannot be called when called from my models.py . When I execute the same line from the shell, it works fine.

I have absolutely no idea why this is happening.

Shell:

$ from django.core.urlresolvers import reverse
$ reverse('images:view', args=[1])
'/images/1/'

models.py

from django.db import models
from django.core.urlresolvers import reverse

class Image(models.Model):
    image = models.ImageField(upload_to='images')
    image_caption = models.CharField(max_length=80, verbose_name='Caption')

    uploaded_at = models.DateTimeField(auto_now_add=True, verbose_name='Date Uploaded')
    modified_at = models.DateTimeField(auto_now=True, verbose_name='Date Modified')

    def __str__(self):
        return self.image_caption

    def edit_image(self):
        return '<a href="%s">Edit</a>' % reverse('images:view', args=[self.id])

    edit_image.short_description = 'Edit Image'
    edit_image.allow_tags = True

admin.py refrencing edit_imagehere

from django.contrib import admin
from images.models import Image

class ImageAdmin(admin.ModelAdmin):
    search_fields = ['image_caption']
    list_display = ['id', 'image_caption', 'edit_image']

admin.site.register(Image, ImageAdmin)

url I'm trying to change the image namespace

url(r'^(?P<pk>\d+)/$', views.DetailView.as_view(), name='view'),

What have i tried?

  • reverse_lazy () instead of reverse ()
  • kwargs instead of arg
  • and things that I don’t even know correctly .: P

trace of TRACEBACK calls

Template error:
In template /home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/contrib/admin/templates/admin/change_list.html, error at line 91
   'NoneType' object is not callable
   81 :         {% endif %}
   82 :       {% endblock %}
   83 :
   84 :       <form id="changelist-form" action="" method="post"{% if cl.formset.is_multipart %} enctype="multipart/form-data"{% endif %}>{% csrf_token %}
   85 :       {% if cl.formset %}
   86 :         <div>{{ cl.formset.management_form }}</div>
   87 :       {% endif %}
   88 : 
   89 :       {% block result_list %}
   90 :           {% if action_form and actions_on_top and cl.full_result_count %}{% admin_actions %}{% endif %}
   91 :            {% result_list cl %} 
   92 :           {% if action_form and actions_on_bottom and cl.full_result_count %}{% admin_actions %}{% endif %}
   93 :       {% endblock %}
   94 :       {% block pagination %}{% pagination cl %}{% endblock %}
   95 :       </form>
   96 :     </div>
   97 :   </div>
   98 : {% endblock %}
   99 : 

Traceback:
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/core/handlers/base.py" in get_response
  139.                 response = response.render()
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/response.py" in render
  105.             self.content = self.rendered_content
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/response.py" in rendered_content
  82.         content = template.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in render
  140.             return self._render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in _render
  134.         return self.nodelist.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in render
  840.                 bit = self.render_node(node, context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/debug.py" in render_node
  78.             return node.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/loader_tags.py" in render
  123.         return compiled_parent._render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in _render
  134.         return self.nodelist.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in render
  840.                 bit = self.render_node(node, context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/debug.py" in render_node
  78.             return node.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/loader_tags.py" in render
  123.         return compiled_parent._render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in _render
  134.         return self.nodelist.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in render
  840.                 bit = self.render_node(node, context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/debug.py" in render_node
  78.             return node.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/loader_tags.py" in render
  62.             result = block.nodelist.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in render
  840.                 bit = self.render_node(node, context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/debug.py" in render_node
  78.             return node.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/loader_tags.py" in render
  62.             result = block.nodelist.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in render
  840.                 bit = self.render_node(node, context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/debug.py" in render_node
  78.             return node.render(context)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/template/base.py" in render
  1196.                     _dict = func(*resolved_args, **resolved_kwargs)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/contrib/admin/templatetags/admin_list.py" in result_list
  288.             'results': list(results(cl))}
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/contrib/admin/templatetags/admin_list.py" in results
  266.             yield ResultList(None, items_for_result(cl, res, None))
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/contrib/admin/templatetags/admin_list.py" in __init__
  258.         super(ResultList, self).__init__(*items)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/contrib/admin/templatetags/admin_list.py" in items_for_result
  185.             f, attr, value = lookup_field(field_name, result, cl.model_admin)
File "/home/ankit/Desktop/Python/Workspace/VirtualEnv3.3.2/local/lib/python3.3/dist-packages/django/contrib/admin/util.py" in lookup_field
  258.                 value = attr()
File "/home/ankit/Desktop/Python/Workspace/SnapShare/images/models.py" in edit_image
  30.         return '<a href="%s">Edit</a>' % reverse('images:view', args=[self.id])

Exception Type: TypeError at /admin/images/image/
Exception Value: 'NoneType' object is not callable

Python Version: 3.3.2

Django Version: 1.6.2

Thanks in advance:)

+3
1

1

reverse_lazy ( ). , URL- .

2

ModelAdmin, "copy-paste-ready":

class ImageAdmin(admin.ModelAdmin):

    # ... the rest of the class ... #

    def edit_image(self, obj):
        return '<a href="%s">Edit</a>' % reverse('images:view', args=[obj.id])

    edit_image.short_description = 'Edit Image'
    edit_image.allow_tags = True

, , .

( urlconf), .

0

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