PyMongo is a library for working with MongoDB from Python. It allows you to access and manipulate data stored in MongoDB using Python.

1. Install the PyMongo library:

Before you can use the PyMongo library, you must first install it. You can do this using pip:

pip install pymongo

2. Connect to MongoDB:

Once you have installed the library, you can connect to MongoDB using the MongoClient class. This class takes in the hostname and port of the MongoDB server as parameters.

from pymongo import MongoClient

client = MongoClient(‘localhost’, 27017)

3. Access a Database:

Once you have connected to MongoDB, you can access a specific database using the dictionary-style access:

db = client[‘my_database’]

4. Access a Collection:

You can access a specific collection within the database using the dictionary-style access:

collection = db[‘my_collection’]

5. Query the Collection:

You can query the collection using the find() method. This method takes in a query document as a parameter and returns a cursor object which can be used to iterate over the results:

cursor = collection.find({‘name’: ‘John’})

for document in cursor:
print(document)

6. Insert Documents:

You can insert documents into the collection using the insert_one() or insert_many() methods. These methods take in a document or a list of documents as parameters:

collection.insert_one({‘name’: ‘John’, ‘age’: 30})

collection.insert_many([
{‘name’: ‘Jane’, ‘age’: 25},
{‘name’: ‘Bob’, ‘age’: 27}
])

7. Update Documents:

You can update documents in the collection using the update_one() or update_many() methods. These methods take in a query document and an update document as parameters:

collection.update_one({‘name’: ‘John’}, {‘$set’: {‘age’: 31}})

collection.update_many({‘age’: {‘$lt’: 30}}, {‘$inc’: {‘age’: 1}})

8. Delete Documents:

You can delete documents from the collection using the delete_one() or delete_many() methods. These methods take in a query document as a parameter:

collection.delete_one({‘name’: ‘John’})

collection.delete_many({‘age’: {‘$gt’: 25}})