Nested Queries in PyMongo

import pprint
from pymongo import MongoClient


client = MongoClient()

Database = client["GFG"]
lecturers = Database["lecture"]

lecturers.insert_many([
   {"l_id":56, "d_id":1, "salary":50000},
   {"l_id":57, "d_id":3, "salary":40000},
   {"l_id":58, "d_id":4, "salary":90000},
   {"l_id":59, "d_id":2, "salary":50000},
   {"l_id":52, "d_id":1, "salary":70000},
   {"l_id":53, "d_id":5, "salary":30000}
])

# retrieving the documents
for x in lecturers.find():
    pprint.pprint(x)

# lecturer records with salary less 
# than 50000 and arrange in ascending order.
pprint.pprint(list(lecturers.find({"salary":
                                  {'$lt':50000}}).sort('salary', 1)))

# lecturer records with salary greater than 40000
# in department_id 1 and sort according to their 
# salary in descending order.
pprint.pprint(list(lecturers.find({'$and':
                                   [{"d_id":1},
                                    {"salary":
                                     {'$gte':50000}}]}).sort("salary", -1)))

import pprint
from pymongo import MongoClient
import datetime


client = MongoClient()
Database = client["GFG"]
books = Database["book"]

books.insert_many([
    {"author":"Samsuel", "book_id":54, "ratings":3,
     "publish":datetime.datetime(1999, 12, 6)},
    
    {"author":"Thomson", "book_id":84, "ratings":4,
     "publish":datetime.datetime(1996, 7, 12)},
    
    {"author":"Piyush Agarwal", "book_id":34, "ratings":1,
     "publish":datetime.datetime(2000, 9, 6)},
    
    {"author":"Shreya Mathur", "book_id":12, "ratings":2, 
     "publish":datetime.datetime(2017, 8, 8)},
    
    {"author":"Antony Sharma", "book_id":98, "ratings":4, 
     "publish":datetime.datetime(2003, 11, 5)},
])

# retrieving the documents
for x in books.find():
    pprint.pprint(x)

# books with ratings greater than 3 published after 2000
pprint.pprint(list(books.find({'$and':
                               [{"ratings":
                                 {'$gt':3}},
                                {"publish":
                                 {'$gt':datetime.datetime(2000, 12, 31)
                                 }
                                }
                               ]
                              }
                             )
                  )
             )

# between 1999-2016
query ={'$and':
        [{"publish":
          {'$gte':datetime.datetime(1999, 1, 1)}}, 
         {"publish":
          {'$lte':datetime.datetime(2016, 12, 31)}}]}

# books with ratings greater than 1
# and published between the year 
# 1999-2016, sort in decreasing order.
pprint.pprint(list(books.find({'$and':
                               [{"ratings":
                                 {'$gt':1}},
                                query]}).sort("publish", -1)))