Create custom analyzer filter for a index in py-elasticsearch-dsl

For create a custom filter we can use token_filter:

turkish = analysis.token_filter('turkish_lowercase', type="lowercase", language="turkish")

We are creating a new lower_case filter for turkish language. Now, we need to create the analyzer:

turkish_lowercase = analyzer('turkish_lowercase',    type = "custom",    tokenizer="standard",    filter=[turkish],)

We put turkish filter directly in the filter parameter, nothing more; we can review the result dictionary with the get_definition function either filter as analyzer.

Finally we apply that analyzer in our Document:

class Document(DocType):    title = Text(        analyzer=turkish_lowercase,        # filter=turkish        )    query = Percolator(    )    # query is a percolator    class Meta:        index = 'titles' # index name        doc_type = '_doc'    def save(self, **kwargs):        return super(Document, self).save(**kwargs)

We will get the next result:

{   "titles":{      "aliases":{      },      "mappings":{         "_doc":{            "properties":{               "query":{                  "type":"percolator"               },               "title":{                  "type":"text",                  "analyzer":"turkish_lowercase"               }            }         }      },      "settings":{         "index":{            "number_of_shards":"5",            "provided_name":"titles",            "analysis":{               "filter":{                  "turkish_lowercase":{                     "type":"lowercase",                     "language":"turkish"                  }               },               "analyzer":{                  "turkish_lowercase":{                     "filter":[                        "turkish_lowercase"                     ],                     "type":"custom",                     "tokenizer":"standard"                  }               }            },            "number_of_replicas":"1",         }      }   }}