django model get_absolute_url not working -

i have seen example of using above method directly on model instance book. not working actually. method removed in latest versions? here code.

in [24]: django_tag out[24]: <tag: django>  in [22]: django_tag.get_absolute_url() --------------------------------------------------------------------------- attributeerror                            traceback (most recent call last) <ipython-input-22-bde20b3ec098> in <module>() ----> 1 django_tag.get_absolute_url()  attributeerror: 'tag' object has no attribute 'get_absolute_url' 

i looked dir function. don't show such method exists. i'm using django v. 1.11.

in [25]: dir(django_tag) out[25]: ['doesnotexist',  'multipleobjectsreturned',  '__class__',  '__delattr__',  '__dict__',  '__dir__',  '__doc__',  '__eq__',  '__format__',  '__ge__',  '__getattribute__',  '__gt__',  '__hash__',  '__init__',  '__init_subclass__',  '__le__',  '__lt__',  '__module__',  '__ne__',  '__new__',  '__reduce__',  '__reduce_ex__',  '__repr__',  '__setattr__',  '__setstate__',  '__sizeof__',  '__str__',  '__subclasshook__',  '__weakref__',  '_check_column_name_clashes',  '_check_field_name_clashes',  '_check_fields',  '_check_id_field',  '_check_index_together',  '_check_local_fields',  '_check_long_column_names',  '_check_m2m_through_same_relationship',  '_check_managers',  '_check_model',  '_check_model_name_db_lookup_clashes',  '_check_ordering',  '_check_swappable',  '_check_unique_together',  '_do_insert',  '_do_update',  '_get_field_display',  '_get_next_or_previous_by_field',  '_get_next_or_previous_in_order',  '_get_pk_val',  '_get_unique_checks',  '_meta',  '_perform_date_checks',  '_perform_unique_checks',  '_save_parents',  '_save_table',  '_set_pk_val',  '_state',  'blog_posts',  'check',  'clean',  'clean_fields',  'date_error_message',  'delete',  'from_db',  'full_clean',  'get_deferred_fields',  'id',  'name',  'objects',  'pk',  'prepare_database_save',  'refresh_from_db',  'save',  'save_base',  'serializable_value',  'slug',  'startup_set',  'unique_error_message',  'validate_unique'] 

models.py

class tag(models.model):      name = models.charfield(max_length=31, unique=true)      slug = models.slugfield(unique=true, help_text='a label url config.')       def __str__(self):          return self.name       class meta:          ordering = ['name'] 

please read docs

class tag(models.model):     name = models.charfield(max_length=31, unique=true)     slug = models.slugfield(unique=true, help_text='a label url config.')      def __str__(self):         return self.name      def get_absolute_url(self):         django.urls import reverse         return reverse('appname.views.viewname', args=[self.slug])      class meta:         ordering = ['name'] 

wiki