❮ Python String Upper Python Remove A Key From Dictionary ❯

Python MongoDB

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

For MongoDB database installation and introduction, please refer to our MongoDB Tutorial.

PyMongo

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

pip Installation

pip is a general-purpose Python package management tool, providing functionalities for searching, downloading, installing, and uninstalling Python packages.

Install pymongo:

$ python3 -m pip3 install pymongo

You can also specify the 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 named demo_test_mongodb.py with the following code:

demo_test_mongodb.py File Code:

#!/usr/bin/python3

import pymongo

Executing the above code file, if no errors occur, indicates successful installation.

Creating a Database

Creating a database requires a MongoClient object and specifying the connection URL and the database name.

In the following example, we create a database named tutorialprodb:

Example

#!/usr/bin/python3

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["tutorialprodb"]

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

Checking if a Database Exists

We can retrieve all databases in MongoDB and check if the 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 "tutorialprodb" in dblist:
  print("The database already exists!")

Note: database_names is deprecated in the latest versions of Python. For Python 3.7+ and later, it has been replaced with list_database_names().

Creating a Collection

Collections in MongoDB are similar to tables in SQL.

Creating a Collection

MongoDB uses a database object to create a collection, as shown in the following example:

Example

#!/usr/bin/python3

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["tutorialprodb"]

mycol = mydb["sites"]

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

Checking if a Collection Exists

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

Example

#!/usr/bin/python3

import pymongo

myclient = pymongo.MongoClient('mongodb://localhost:27017/')

mydb = myclient['tutorialprodb']

collist = mydb.list_collection_names()

# collist = mydb.collection_names()
if "sites" in collist:   # Check if the "sites" collection exists
  print("Collection already exists!")

Note: collection_names is deprecated in the latest versions of Python, replaced by list_collection_names() in Python 3.7+ versions.

Insert, Delete, Update, Query Operations

The table below lists more operations for MongoDB, click on the specific links for details:

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

❮ Python String Upper Python Remove A Key From Dictionary ❯