code: def listBlockParents(self, block_name=""):
          
          if not block_name:
              msg = " DBSBlock/listBlockParents. Block_name must be provided as a string or a list. \
                  No wildcards allowed in block_name/s."
              dbsExceptionHandler('dbsException-invalid-input', msg)
          elif isinstance(block_name, basestring):
              try:
                  block_name = str(block_name)
                  if '%' in block_name or '*' in block_name:
                      dbsExceptionHandler("dbsException-invalid-input", "DBSReaderModel/listBlocksParents: \
                      NO WILDCARDS allowed in block_name.")
              except:
                  dbsExceptionHandler("dbsException-invalid-input", "DBSBlock/listBlockParents. Block_name must be \
                  provided as a string or a list. No wildcards allowed in block_name/s .")
          elif type(block_name) is list:
              for b in block_name:
                  if '%' in b or '*' in b:
                      dbsExceptionHandler("dbsException-invalid-input", "DBSReaderModel/listBlocksParents: \
                              NO WILDCARDS allowed in block_name.")
          else:
              msg = "DBSBlock/listBlockParents. Block_name must be provided as a string or a list. \
                  No wildcards allowed in block_name/s ."
              dbsExceptionHandler("dbsException-invalid-input", msg)
          conn = self.dbi.connection()
          try:
              results = self.blockparentlist.execute(conn, block_name)
              return results
          finally:
              if conn:
                  conn.close()
docs: list parents of a block