python - mongodb get element in multi array -

python - mongodb get element in multi array -

i have mongodb document this:

{ "post":[ { "name": "post1", "part": [ { "name": "part1", ... },{ "name": "part2", ... } ] },{ "name": "post2", "part": [ { "name": "part3", ... },{ "name": "part4", ... } ] } ... ] }

i want output this:

{ "post": [ { "part":[ { "name": "part2" } ] } ] }

my query this:

db.find_one({"_id": 123},{ "post.%s.part.%s.name" % (0, 1) : 1 })

i known index of list post (is 0) , part (is 1)

i can't index of output, can help me element of array ? have seek $slice, how query $slice in multi part of array thanks!

projection can't project out specific elements except matching $. can restrict field "post.part.name" (but still getting field value each element of bottom-level array).

python mongodb