code: def namedb_get_num_names( cur, current_block, include_expired=False ):
      
      unexpired_query = ""
      unexpired_args = ()
  
      if not include_expired:
          # count all names, including expired ones
          unexpired_query, unexpired_args = namedb_select_where_unexpired_names( current_block )
          unexpired_query = 'WHERE {}'.format(unexpired_query)
  
      query = "SELECT COUNT(name_records.name) FROM name_records JOIN namespaces ON name_records.namespace_id = namespaces.namespace_id " + unexpired_query + ";"
      args = unexpired_args
  
      num_rows = namedb_select_count_rows( cur, query, args, count_column='COUNT(name_records.name)' )
      return num_rows
docs: Get the number of names that exist at the current block