Using PyMongo to Access MongoDB

mongodb mongo python pymongo

Install pymongo

pip install pymongo

Connect to MongoDB

User name and password must be percent-escaped with urllib.parse.quote_plus() if they are from insternet.

from pymongo import MongoClient
from urllib.parse
username = urllib.parse.quote_plus('user')
password = urllib.parse.quote_plus('pass/word') # 'pass%2Fword'
MongoClient('mongodb://%s:%s@127.0,0,1' % (username, password))

Mongodb URI example

from pymongo import MongoClient
uri = "mongodb://user:password@example.com/the_database?authMechanism=SCRAM-SHA-1"
MongoClient(uri)

MongoClient Arguments example

from pymongo import MongoClient
client = MongoClient(host='example.com',
                    username='user',
                    password='password',
                    authSource='the_database',
                    authMechanism='SCRAM-SHA-1')
db = client['database name']

Create you own MongoDB class

ini file (mongodb.ini)

[mongodb]
DATABASE: userdb
USER: dbuser
PASSWORD: dbpassword
HOST: db.sample.com
PORT: 27017
AUTHSOURCE: userdb

MongoDB class

  import configparser
  from pymongo import MongoClient

  class MongoDB:
      """
      Connect to MongoDB. It opens connection and closes the connection when it is destroyed.
      """
      def __init__(self):
          self.config=configparser.ConfigParser()
          self.config.read_file(open('<your mongodb properties file name here>'))
          self.cnx = None

      def __enter__(self):
          print("enter")
          if self.cnx is not None:
              raise RuntimeError('Aready connected')
          self.cnx = MongoClient(host=self.config["mongodb"]["HOST"],
                      username=self.config["mongodb"]["USER"],
                      password=self.config["mongodb"]["PASSWORD"],
                      port=int(self.config["mongodb"]["PORT"]),
                      authSource=self.config["mongodb"]["AUTHSOURCE"] )
          return self.cnx[self.config["mongodb"]["DATABASE"]]

      def __exit__(self, exe_ty, exc_val, tb):
          self.cnx.close()
          self.cnx = None

Using MongoDB class

Query and command

mongo = MongoDB()
with mongo as db:
  result = db.campuses.find()
  for row in result:
      print(row)
  print(db.accounts.find({"firstName":"John"}).count())
  print(db.command("buildinfo"))
  print(db.command("usersInfo", "<username>"))

bulk_write - Send a batch of write operations to the server.
Requests are passed as a list of write operation instances ( InsertOne, UpdateOne, UpdateMany, ReplaceOne, DeleteOne, or DeleteMany).

from pymongo import InsertOne, DeleteOne, ReplaceOne

mongo = MongoDB()
with mongo as db:
    requests = [InsertOne({'y': 1}), DeleteOne({'x': 1}),
             ReplaceOne({'w': 1}, {'z': 1}, upsert=True)]
    result = db.test.bulk_write(requests)
    print("Inerted: %s, Deleted: %s, Modified: %s, Upserted_ids: %s" %
        (result.inserted_count, result.deleted_count, result.modified_count, result.upserted_ids))

insert_one - insert a single document

mongo = MongoDB()
with mongo as db:
  result = db.test.insert_one({'x': 1})
  print(result.inserted_id)

insert_many - insert an iterable of documents

mongo = MongoDB()
with mongo as db:
 result = db.test.insert_many([{'x': i} for i in range(2)])
 print(result.inserted_ids)

replace_one - replace a single document matching filter

mongo = MongoDB()
with mongo as db:
  result = db.test.replace_one({'x': 1}, {'y': 1})
  print("%s, %s" % (result.matched_account, result.modified_count))

The following operation will install a new document if a matching document does not exist.

result = db.test.replace_one({'x': 1}, {'x': 1}, True)

update_one - update a single document matching the filter

mongo = MongoDB()
with mongo as db:
  result = db.test.update_one({'x': 1}, {'$inc': {'x': 3}})
  print("%s, %s" % (result.matched_account, result.modified_count))

update_many - update one or many documents that match the filter

mongo = MongoDB()
with mongo as db:
  result = db.test.update_many({'x': 1}, {'$inc': {'x': 3}})
  print("%s, %s" % (result.matched_account, result.modified_count))

delete_one and delete_many

mongo = MongoDB()
with mongo as db:
  result = db.test.delete_one({'x': 1})
  print(result.deleted_count)
  result = db.test.delete_many({'x': 1})
  print(result.deleted_count)

find_one - find a single document from database

mongo = MongoDB()
with mongo as db:
  result = db.test.find_one({'x': 1})
  print(result)

find_one_and_delete

mongo = MongoDB()
with mongo as db:
  result = db.test.find_one_and_delete({'x': 1}, projection={'_id': False})
  print(result)

find_one_and_update and find_one_and_replace

mongo = MongoDB()
with mongo as db:
  result = db.test.find_one_and_replace({'x': 1}, {'y': 1})
  print(result)
  result = db.test.find_one_and_update(
              {'_id': 'userid'},
              {'$inc': {'seq': 1}},
              {'$set': {'done': True}},
              projection={'seq': True, '_id': False},
              upsert=True,
              return_document=ReturnDocument.AFTER)
  print(result)

Sorting

mongo = MongoDB()
with mongo as db:
  result = db.test.find().sort("serialNumber",1)
  for row in result:
      print(row)
  # sort multiple attributes
  result = db.test.find().sort((("serialNumber",1),("Name",1)))
  for row in result:
      print(row)

Find by ObjectId

from bson.objectid import ObjectId
mongo = MongoDB()
with mongo as db:
  result = db.test.find_one("_id": ObjectId("59a86292134a7100144992c1"))
  print(result)

Reference:
Collection level operations
Database level operations
Database Commands
https://www.mongodb.com/blog/post/getting-started-with-python-and-mongodb
http://api.mongodb.com/python/current/examples/authentication.html
http://api.mongodb.com/python/current/api/pymongo/mongo_client.html#pymongo.mongo_client.MongoClient

Written on October 20, 2017