python - union of two mongoDB documents -

i have many documents in "name" there, have find union of documents having same name value, eg:

{"name":"apple iphone 6","memory":"32gb"}, {"name":"apple iphone 6","memory":"16gb"} 

required result is

{"name":"apple iphone 6","memory":"16gb/32gb"} 

you can result aggregation

db.coll.aggregate([     { "$group" : {             "_id" : "$name",             "memory": { "$addtoset": "$memory" }       }} ]); 

output

{ "_id": "apple iphone 6", "memory": ["16gb", "32gb"]} 

then use array join method on result.memory