code: def combine_dicts(recs):
      
      if not recs:
          return None
  
      if len(recs) == 1:
          return recs.pop()
  
      new_rec = {}
      for rec in recs:
          for k, v in rec.iteritems():
              if k in new_rec:
                  new_rec[k] = "%s, %s" % (new_rec[k], v)
              else:
                  new_rec[k] = v
      return new_rec
docs: Combine a list of recs, appending values to matching keys