def getCategories(items):
  cats = set()
  for i in items:
    if i['categories']:
      cats.update(i['categories'])
  return cats

###
### Template context operations
###
Turns a language name (en-us) into a locale name (en_US). If 'to_lower' is
dataset/ETHPy150Open DeanCutlet/filestack/views.py/getCategories--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/utils/translation/trans_real.py/to_locale