new_contents: from portality import models
  
  # first thing to do is delete suggestions which are marked "waiting for answer"
  
  q = {
      "query" : {
          "bool" : {
              "must" : [
                  {"term" : {"admin.application_status.exact" : "waiting for answer"}}
              ]
          }
      }
  }
  
  batch_size = 1000
  total=0
  
  batch = []
  suggestion_iterator = models.Suggestion.iterall(page_size=10000)
  for s in suggestion_iterator:
      
      issns = s.bibjson().get_identifiers(s.bibjson().P_ISSN) + s.bibjson().get_identifiers(s.bibjson().E_ISSN)
      
      delete_0000 = True
      if len(issns) == 1 and issns[0] == '0000-0000':
          print 'suggestion {0} has only 1 id, 0000-0000, not deleting it'
          delete_0000 = False
      
      if delete_0000:
          s.bibjson().remove_identifiers(id='0000-0000')
          s.prep()
          batch.append(s.data)
      
      if len(batch) >= batch_size:
          total += len(batch)
          print "writing", len(batch), "; total so far", total
          models.Suggestion.bulk(batch)
          batch = []
  
  if len(batch) > 0:
      total += len(batch)
      print "writing", len(batch), "; total so far", total
      models.Suggestion.bulk(batch)
  
  
  total = 0
  batch = []
  journal_iterator = models.Journal.iterall(page_size=10000)
  for j in journal_iterator:
      
      issns = j.bibjson().get_identifiers(j.bibjson().P_ISSN) + j.bibjson().get_identifiers(j.bibjson().E_ISSN)
      
      delete_0000 = True
      if len(issns) == 1 and issns[0] == '0000-0000':
          print 'journal {0} has only 1 id, 0000-0000, not deleting it'
          delete_0000 = False
      
      if delete_0000:
          j.bibjson().remove_identifiers(id='0000-0000')
          j.prep()
          batch.append(j.data)
      
      if len(batch) >= batch_size:
          total += len(batch)
          print "writing", len(batch), "; total so far", total
          models.Journal.bulk(batch)
          batch = []
  
  if len(batch) > 0:
      total += len(batch)
      print "writing", len(batch), "; total so far", total
      models.Journal.bulk(batch)
  
subject: add migration script to delete 0000-0000 issns