python - How to create a custom django filter tag -

i having trouble in getting site recognise custom template tags. have following dir structure:

• project_name
  • project_name
    • templatetags
      • _ __init __ _.py
      • getattribute.py
    • views
      • _ __init __ _.py
      • index.html
    • views
    • settings.py
    • main.py
    • manage.py
    • urls.py
  • nbproject

then have added installed_apps:

installed_apps = ( #    'django.contrib.auth',     'django.contrib.contenttypes', #    'django.contrib.sessions',     'django.contrib.sites',     'project_name' ) 

i reference inside template this:

{% load getattribute %} {%  header in headers %}     <td>{{ obj|getattribute:header }}</td> {% endfor %} 

the error follows:

could not import controllers.eventcontroller. error was: no module named project_name

any appreciated this:

tia

andrew

update:

the site works cannot template tags work. if remove project_name installed_apps following error:

exception value: 'getattribute' not valid tag library: not load template library django.templatetags.getattribute, no module named getattribute

the error becaus have wrong folder's structure, think must read docs, tutorial (part1) explains right structure:

you have project isn't same thing app:

• project_name
  • app_name
    • templatetags
      • getattribute.py
    • models.py
    • views.py
• settings.py
• manage.py

and in installed_apps:

installed_apps = ( #    'django.contrib.auth',      'django.contrib.contenttypes', #    'django.contrib.sessions',      'django.contrib.sites',      'project_name.app_name', ) 

that all