Django manager for case-insensitive duplicate checking

CaseInsensitiveManager.py

#Based on https://gist.github.com/rtorr/3148833#
#Extended to take a list of fields to replace the query for


class CaseInsensitiveManager(models.Manager):
    def __init__(self, fields=None, *args, **kwargs):
         if fields != None:
            self.fields = fields
         super(CaseInsensitiveManager, self).__init__(*args, **kwargs)

    def filter(self, **kwargs):
        for field in self.fields:
            if field in kwargs:
                kwargs[field+'__iexact'] = kwargs[field]
                del kwargs[field]
        return super(CaseInsensitiveManager, self).filter(**kwargs)

    def get(self, **kwargs):
        for field in self.fields:
            if field in kwargs:
                kwargs[field+'__iexact'] = kwargs[field]
                del kwargs[field]
        return super(CaseInsensitiveManager, self).get(**kwargs)

#Example:
#class MyModel(models.Model):
#  myfield = models.CharField(max_length=50, unique=True, db_index=True)
#  objects = BrandManager(fields=[field,])
#  ...