  from psycopg2.extras import DateRange, DateTimeTZRange, NumericRange, Range
  
  from django.contrib.postgres import forms, lookups
  from django.db import models
  from django.utils import six
  
  from .utils import AttributeSetter
  
  __all__ = [
      'RangeField', 'IntegerRangeField', 'BigIntegerRangeField',
 
</s> remove from django.utils import six
 </s> add  </s> remove from django.utils import six
 </s> add  </s> remove from django.utils import six
 </s> add  </s> remove from django.utils import six
 </s> add  </s> remove from django.utils import six
 </s> add 
  from psycopg2.extras import DateRange, DateTimeTZRange, NumericRange, Range
  
  from django.contrib.postgres import forms, lookups
  from django.db import models

  
  from .utils import AttributeSetter
  
  __all__ = [
      'RangeField', 'IntegerRangeField', 'BigIntegerRangeField',
keep keep keep keep replace keep keep keep keep keep
 Refs #23919 -- Removed six.<various>_types usage

Thanks Tim Graham and Simon Charette for the reviews. 
django/contrib/postgres/fields/ranges.py