code: def format_servers(servers):
      
      configs = []
      if not isinstance(servers, list):
          raise ValueError("server's config must be list")
      _type = type(servers[0])
      if _type == dict:
          return servers
      if (sys.version_info[0] == 3 and _type in [str, bytes]) \
              or (sys.version_info[0] == 2 and _type in [str, unicode]):
          for config in servers:
              configs.append(parse_url(config))
      else:
          raise ValueError("invalid server config")
      return configs
docs: :param servers: server list, element in it can have two kinds of format.
  
      - dict
  
      servers = [
          {'name':'node1','host':'127.0.0.1','port':10000,'db':0},
          {'name':'node2','host':'127.0.0.1','port':11000,'db':0},
          {'name':'node3','host':'127.0.0.1','port':12000,'db':0},
          ]
  
  
      - url_schema
  
      servers = ['redis://127.0.0.1:10000/0?name=node1',
                  'redis://127.0.0.1:11000/0?name=node2',
                  'redis://127.0.0.1:12000/0?name=node3'
          ]