What's the functionality of "path" in ES_dsl.Q()?

Question

I have a statement: ES_dsl.Q('nested', path='student', query=nest_filter) What kind of role does the "path" play in the above one?

Answer 1

The path is simply the path to the nested field you're using in your query.

In nest_filter, you need to reference your nested field as student.xyz.

Check the equivalence in the query below:

GET /_search
{
    "query": {
        "nested" : {
            "path" : "student",           <--- this is the path
            "query" : {                   <--- this is nest_filter
                "bool" : {
                    { "match" : {"student.name" : "john"} },
                    { "range" : {"student.age" : {"gt" : 20}} }
                    ]
                }
            }
        }
    }
}