def availability_zone_list(request):
 try:
  if api.cinder.extension_supported(request, 'AvailabilityZones'):
   return api.cinder.availability_zone_list(request)
  return []
 except Exception:
  exceptions.handle(request, _('Unable to retrieve volumes availability zones.'))
  return []

def availability_zone_list ( request ) : try : if api . cinder . extension_supported ( request , 'AvailabilityZones' ) : return api . cinder . availability_zone_list ( request ) return [ ] except Exception : exceptions . handle ( request , _ ( 'Unable to retrieve volumes availability zones.' ) ) return [ ]
utility method to retrieve a list of availability zones .