老师，您好！
我运行python的es_type.py，为了生成elasticsearch的索引，但报错了，代码如下：

# -*- coding: utf-8 -*-

from elasticsearch_dsl import DocType, Date, Nested, Boolean, \
    analyzer, Completion, Keyword, Text, Integer

from elasticsearch_dsl.analysis import CustomAnalyzer as _CustomAnalyzer

from elasticsearch_dsl.connections import connections
connections.create_connection(hosts=["localhost"])

class CustomAnalyzer(_CustomAnalyzer):
    def get_analysis_definition(self):
        return {}


ik_analyzer = CustomAnalyzer("ik_max_word", filter=["lowercase"])

class ArticleType(DocType):
    suggest = Completion(analyzer=ik_analyzer)
    title = Text(analyzer="ik_max_word")
    time = Date()
    domain = Text(analyzer="ik_max_word")
    article_url = Keyword()

    class Meta:
        index = "AJobbole"
        doc_type = "article"


if __name__ == "__main__":
    ArticleType.init()

出错信息如下：

Traceback (most recent call last):
  File "E:/homework/python/ScrapySpider/spider/spider/models/es_types.py", line 33, in <module>
    ArticleType.init()
  File "E:\Envs\py3\lib\site-packages\elasticsearch_dsl\document.py", line 136, in init
    i.save(using=using)
  File "E:\Envs\py3\lib\site-packages\elasticsearch_dsl\index.py", line 269, in save
    if not self.exists(using=using):
  File "E:\Envs\py3\lib\site-packages\elasticsearch_dsl\index.py", line 380, in exists
    return self._get_connection(using).indices.exists(index=self._name, **kwargs)
  File "E:\Envs\py3\lib\site-packages\elasticsearch_dsl\index.py", line 108, in _get_connection
    "You cannot perform API calls on the default index.")
ValueError: You cannot perform API calls on the default index.

Process finished with exit code 1

ValueError: You cannot perform API calls on the default index.

是哪里错了呢？这段代码我基本是参照您视频教程里打出来的。
请老师提示，谢谢~