Python MongoDB

MongoDB is one of the most popular NoSQL databases, using the BSON data type (similar to JSON).

For MongoDB database installation and introduction, check out our MongoDB tutorial.

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PyMongo

To connect Python to MongoDB, you need a MongoDB driver. Here we use the PyMongo driver.

pip Installation

pip is a general-purpose Python package management tool that provides functions for finding, downloading, installing, and uninstalling Python packages.

Install pymongo:

$ python3 -m pip3 install pymongo

You can also specify a version to install:

$ python3 -m pip3 install pymongo==3.5.1

Update pymongo command:

$ python3 -m pip3 install --upgrade pymongo

easy_install Installation

Older versions of Python can use easy_install for installation. easy_install is also a Python package management tool.

$ python -m easy_install pymongo

Update pymongo command:

$ python -m easy_install -U pymongo

Testing PyMongo

Next, we can create a test file demo_test_mongodb.py with the following code:

demo_test_mongodb.py File Code:

#!/usr/bin/python3
 
import pymongo

If no errors occur when executing the above code file, it means the installation was successful.

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Creating a Database

Creating a Database

To create a database, you need to use the MongoClient object and specify the connection URL address and the database name to be created.

In the following example, we create the database runoobdb:

Example

#!/usr/bin/python3
 
import pymongo
 
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]

Note: In MongoDB, a database is only created after content is inserted! That is, after creating a database, you must create a collection (data table) and insert a document (record) for the database to actually be created.

Checking if a Database Already Exists

We can read all databases in MongoDB and check if a specified database exists:

Example

#!/usr/bin/python3
 
import pymongo
 
myclient = pymongo.MongoClient('mongodb://localhost:27017/')
 
dblist = myclient.list_database_names()
# dblist = myclient.database_names() 
if "runoobdb" in dblist:
  print("Database already exists!")

Note: database_names has been deprecated in the latest versions of Python. In Python 3.7+ and later, it has been renamed to list_database_names().

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Creating a Collection

Collections in MongoDB are similar to tables in SQL.

Creating a Collection

MongoDB uses database objects to create collections, as shown in the following example:

Example

#!/usr/bin/python3
 
import pymongo
 
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
 
mycol = mydb["sites"]

Note: In MongoDB, a collection is only created after content is inserted! That is, after creating a collection (data table), you must insert a document (record) for the collection to actually be created.

Checking if a Collection Already Exists

We can read all collections in the MongoDB database and check if a specified collection exists:

Example

#!/usr/bin/python3
 
import pymongo
 
myclient = pymongo.MongoClient('mongodb://localhost:27017/')
 
mydb = myclient['runoobdb']
 
collist = mydb. list_collection_names()
# collist = mydb.collection_names()
if "sites" in collist:   # Check if sites collection exists
  print("Collection already exists!")

Note: collection_names has been deprecated in the latest versions of Python. In Python 3.7+ and later, it has been renamed to list_collection_names().

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Insert, Delete, Update, and Query Operations

The table below lists more MongoDB operations. Click the specific links for details:

No.	Function
1	Insert Data
2	Query Data
3	Update Data
4	Sort Data
5	Delete Data