Searching documents with nested fields, using "exists" filter?

I have a document similar to this:

class MyDoc(DocType):
   field1 = String()
   field2 = Nested(properties={"field3": String(), "field4: String()})

I would like to search for all documents that actually have field3…

As a control, I have tried:

>>> s = MyDoc.search()
>>> s.filter("exists", field="field1").count()
>>> 26870

But, with the nested field, it doesn’t seem to work even though I know that there are such documents:

>>> s.filter("exists", field="field2").count()
>>> 0
>>> s.filter("exists", field="field2.field3").count()
>>> 0
>>> s.filter("exists", field="field2__field3").count()
>>> 0

So, my question is: how to search for documents that have a specified nested field? (Working with elasticsearch_dsl v0.0.5.dev0)

[njoannin]

I think I found it:

s = MyDoc.search()
s = s.filter('nested', path='field2', filter=F('exists', field="field2.field3"))

And now it works.

Thanks again for your help!

[honzakral]

@osama-v8 Q() serves the same purpose now