How to backup a collection using pymongo. Read the documents using pymongo's find and filter the result using limitimg_query Insert all the matched documents by converting the cursor to a list

pymongoBackup.py

from pymongo import MongoClient
from datetime import datetime
target_client = MongoClient('localhost', 12345)
from_db = target_client['existing_db']
from_col = 'collection'
to_db = target_client['backup_db']
to_col = 'backup'

def createBackup(from_db, from_col, to_db, to_col, limiting_query=None):
    back_up_cursor = from_db[from_col].find(limiting_query)
    to_db[to_col].insert(list(back_up_cursor))

createBackup(from_db, from_col, to_db, to_col, {'time' : {'$lt' : datetime.now()}})