title: elasticsearch python regex query
body: <p>I want to execute queries like "my * is" which should yield results like "my name is", "my car is" etc.</p>
  
  <pre><code>from elasticsearch import Elasticsearch
  from elasticsearch_dsl import Search
  client = Elasticsearch([
      {'host': 'localhost', 'port':9200}
      ])
  s = Search(using=client, index="index_name") \
      .query('regexp', title="my * is")
  response = s.execute()
  </code></pre>
  
  <p>But I am getting empty response.</p>