performance loop while get data from gridFS - mongodb

Question

I'm using pymongo to get the data from gridFS, the loop while getting this data is really slow.
Is it possible to avoid that loop, or is any way to do that faster??
from pymongo import MongoClient
from pprint import pprint
import bson
from gridfs import GridFS
import json
import pandas as pd
client = MongoClient()
client.database_names()
db = client['MC']
fs = GridFS(db, collection="MC")
db.collection_names(include_system_collections=False)
collectionFiles = db['MC.files']
collectionChunk = db['MC.chunks']
files = db['MC.files'].find({"metadata.Feature0": "00011"})
for n in files:
file_id = n['_id']
chunks = db['MotorCalculo.chunks'].find({"files_id": file_id})
bsondData = (fs.get(file_id).read())
decData = bsondData.decode()
jsonData = json.loads(decData)
F1 = jsonData['Feature1']
F2 = jsonData['Feature2']

Answer 1

If you have enough RAM, it should be faster to access file groups and not make as many calls to mongo.
You can try something like this:
batch_file_id = ['#1', '#2', '#3', '#4']
chunks = db['MotorCalculo.chunks'].find('{\"files_id\" : {\"$in\":[{\"$oid\":\"' + '\"}, {\"$oid\":\"'.join(batch_file_id) + '\"}]}}')
...
batch_file_id
Out[1]: ['#1', '#2', '#3', '#4']
'{\"files_id\" : {\"$in\":[{\"$oid\":\"' + '\"}, {\"$oid\":\"'.join(batch_file_id) + '\"}]}}'
Out[2]: '{"files_id" : {"$in":[{"$oid":"#1"}, {"$oid":"#2"}, {"$oid":"#3"}, {"$oid":"#4"}]}}'
Regards!!