code: def namedb_get_num_names_in_namespace( cur, namespace_id, current_block ):
      
      unexpired_query, unexpired_args = namedb_select_where_unexpired_names( current_block )
  
      query = "SELECT COUNT(name_records.name) FROM name_records JOIN namespaces ON name_records.namespace_id = namespaces.namespace_id WHERE name_records.namespace_id = ? AND " + unexpired_query + " ORDER BY name;"
      args = (namespace_id,) + 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 in a given namespace