MongoDB - Connect with Python

Last updated 27^th July 2022

Objective

Public Cloud Databases allow you to focus on building and deploying cloud applications while OVHcloud takes care of the database infrastructure and maintenance in operational conditions.

This guide explains how to connect to a MongoDB database instance with one of the world's most famous programming language: Python.

You can find an example on the Github examples repository.

Requirements

• A Public Cloud project in your OVHcloud account
• Access to the OVHcloud Control Panel
• A MongoDB database running on your OVHcloud Public Cloud Databases (this guide can help you to meet this requirement)
• Configure your MongoDB instance to accept incoming connections
• A Python environment with a stable version and public network connectivity (Internet). This guide was made using Python 3.9.5.

Concept

A MongoDB instance can be managed through multiple ways. One of the easiest, yet powerful, is to use a Command Line Interface (CLI), as shown in our guide : Connect to MongoDB with CLI.

Another way is to interact directly using a programming language, such as Python. Python is one of the major programming languages in the world, especially in the Data ecosystem. MongoDB provides official Python drivers, allowing us to connect and manage a MongoDB instance from code.

In order to do so, we will need to set up our Python environment with MongoDB drivers, then configure our Public Cloud Databases for MongoDB instances to accept incoming connections, and finally code in Python to perform a few example actions.

Instructions

Set up your Python environment

To interact with your MongoDB instance using Python, your development environment needs to be configured with:

• A compatible version of Python.
• MongoDB official driver, called PyMongo, or Motor, when working asynchonously with MongoDB.

This guide will focus on the use of PyMongo, which covers most of the use cases.

Please follow the official MongoDB documentation for Python drivers to get the latest information.

At the end of the documentation page for PyMongo, you will find a compatibility matrix between Python versions and PyMongo driver. Follow this accordingly.

Once your Python environment is set up and you begin executing a python --version in your command line interface (CLI), you should see information about the version as shown below :

laptop$ python --version
Python 3.9.5

In the same console, by typing a pip list check if pymongo is correctly installed :

laptop$  pip list           
Package                Version
---------------------- -------------------
brotlipy               0.7.0
certifi                2021.5.30
cffi                   1.14.6
chardet                4.0.0
conda                  4.10.3
conda-package-handling 1.7.3
cryptography           3.4.7
idna                   2.10
pip                    21.1.3
pycosat                0.6.3
pycparser              2.20
pymongo                3.12.0
(...)

In my case, I can find Python 3.9.5, and PyMongo 3.12. Based on official MongoDB compatibility matrix linked previously, I will be able to connect to MongoDB instances in versions 4.x and 5. This is compliant with my current MongoDB 4.4 instance.

Finally, copy the IP address of your Python environment and save it for later. If you don't know how to get your IP, please visit a website like www.WhatismyIP.com from your station hosting the Python environment. In our example, we will use the (fake) IP 109.190.200.59.

We will now follow the official MongoDB documentation to perform our first connection with Python.

Connect with Python

In your Python environment, let's try a connection. To be sure that we are indeed connected, we will insert two objects. Create a file called basic_insert.py. Insert the code below with your own credentials.

As shown in the code, we use the PyMongo official driver. Use the official PyMongo documentation for exhaustive command list : https://docs.mongodb.com/drivers/pymongo/.

from pymongo import MongoClient
from pymongo.errors import ConnectionFailure

# Establishing connection
try:
    # MongoClient('mongodb://username:password@hostnameOrReplicaset/?tls=True') replica by your own Service URI
    uri = 'mongodb+srv://<username>:<password>@mongodb-e49d02ee-o2626ab53.database.cloud.ovh.net/admin?replicaSet=replicaset'
    connect = MongoClient(uri)
    print("MongoDB cluster is reachable")
    print(connect)
except ConnectionFailure as e:
    print("Could not connect to MongoDB")
    print(e)

After executing your Python code, result shown in the CLI should be like this :

laptop$ python basic_insert.py
MongoDB cluster is reachable
MongoClient(host=['node1-123456789.database.cloud.ovh.net:27017'], document_class=dict, tz_aware=False, connect=True, ssl=True)

If not, your CLI should give you more details about the issue, for example :

• Authentication failed : could be an error with your user login or password;
• nodename nor servname provided, or not known : could be a wrongly typed hostname;
• Connection reset by peer : usually due to connection without secure TLS mode. use tls=true parameter.

Once connected, you can perform multiple operations, for example a few inserts and a find() inside a collection :

# Connecting or switching to the database
db = connect.myDb

# Creating or switching to demoCollection
collection = db.demoCollection

#first document
document1 = {
        "name":"John",
        "age":24,
        "location":"New York"
        }
#second document
document2 = {
        "name":"Marianne",
        "age":21,
        "location":"Paris"
        }

# Inserting both documents one by one
collection.insert_one(document1)
collection.insert_one(document2)

# Printing the data inserted
cursor = collection.find()
for record in cursor:
    print(record)

In this example, we insert 2 objects inside a collection called demoCollection, then we perform a find() operations in this collection, looking for all the objects.

The result here is for the print(record) :

{'_id': ObjectId('6140b59fd68c16b38fe677ba'), 'name': 'John', 'age': 24, 'location': 'New York'}
{'_id': ObjectId('6140b5a0d68c16b38fe677bb'), 'name': 'Marianne', 'age': 21, 'location': 'Paris'}

This code correctly found the two previously inserted objects. It means that here we were able to connect to the MongoDB instance, insert data, and look for this data. Congratulations! Everything is working properly.

Go further

MongoDB capabilities

Configuring vRack for Public Cloud

Visit our dedicated Discord channel: https://discord.gg/ovhcloud. Ask questions, provide feedback and interact directly with the team that builds our databases services.

Join our community of users on https://community.ovh.com/en/.

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