django in_group template tag

frontend_tags.py

# -*- coding: utf-8 -*-                                                                                          
                                                                                                                 
from django import template                                                                                      
from django.utils.encoding import force_unicode                                                                  
                                                                                                                 
register = template.Library()                                                                                    
                                                                                                                 
@register.filter                                                                                                 
def in_group(user, groups):                                                                                      
    """Returns a boolean if the user is in the given group, or comma-separated                                   
    list of groups.                                                                                              
                                                                                                                 
    Usage::                                                                                                      
                                                                                                                 
        {% if user|in_group:"Friends" %}                                                                         
        ...                                                                                                      
        {% endif %}                                                                                              
                                                                                                                 
    or::                                                                                                         
                                                                                                                 
        {% if user|in_group:"Friends,Enemies" %}                                                                 
        ...                                                                                                      
        {% endif %}                                                                                              
                                                                                                                 
    """                                                                                                          
    group_list = force_unicode(groups).split(',')                                                                
    return bool(user.groups.filter(name__in=group_list).values('name'))