Overview
In this guide, you can learn how to use PyMongo to perform bulk operations. Bulk operations reduce the number of calls to the server by performing multiple write operations in a single method.
The Collection and MongoClient classes both provide a bulk_write() method. When calling bulk_write() on a Collection instance, you can perform multiple write operations on a single collection. When calling bulk_write() on a MongoClient instance, you can perform bulk writes across multiple namespaces. In MongoDB, a namespace consists of the database name and the collection name in the format <database>.<collection>.
Important
To perform bulk operations on a MongoClient instance, ensure that your application meets the following requirements:
Uses PyMongo v4.9 or later
Connects to MongoDB Server v8.0 or later
Sample Data
The examples in this guide use the sample_restaurants.restaurants and sample_mflix.movies collections from the Atlas sample datasets. To learn how to create a free MongoDB Atlas cluster and load the sample datasets, see the Get Started with PyMongo tutorial.
Define the Write Operations
For each write operation you want to perform, create an instance of one of the following operation classes:
InsertOneUpdateOneUpdateManyReplaceOneDeleteOneDeleteMany
Then, pass a list of these instances to the bulk_write() method.
Important
Ensure that you import the write operation classes into your application file, as shown in the following code:
from pymongo import InsertOne, UpdateOne, UpdateMany, ReplaceOne, DeleteOne, DeleteMany
The following sections show how to create instances of the preceding classes, which you can use to perform collection and client bulk operations.
Insert Operations
To perform an insert operation, create an instance of InsertOne and specify the document you want to insert. Pass the following keyword arguments to the InsertOne constructor:
namespace: The namespace in which to insert the document. This argument is optional if you perform the bulk operation on a single collection.document: The document to insert.
The following example creates an instance of InsertOne:
operation = InsertOne( namespace="sample_restaurants.restaurants", document={ "name": "Mongo's Deli", "cuisine": "Sandwiches", "borough": "Manhattan", "restaurant_id": "1234" } )
You can also create an instance of InsertOne by passing an instance of a custom class to the constructor. This provides additional type safety if you're using a type-checking tool. The instance you pass must inherit from the TypedDict class.
Note
TypedDict in Python 3.7 and Earlier
The TypedDict class is in the typing module, which is available only in Python 3.8 and later. To use the TypedDict class in earlier versions of Python, install the typing_extensions package.
The following example constructs an InsertOne instance by using a custom class for added type safety:
class Restaurant (TypedDict): name: str cuisine: str borough: str restaurant_id: str operation = pymongo.InsertOne(Restaurant( name="Mongo's Deli", cuisine="Sandwiches", borough="Manhattan", restaurant_id="1234"))
To insert multiple documents, create an instance of InsertOne for each document.
Note
_id Field Must Be Unique
In a MongoDB collection, each document must contain an _id field with a unique value.
If you specify a value for the _id field, you must ensure that the value is unique across the collection. If you don't specify a value, the driver automatically generates a unique ObjectId value for the field.
We recommend letting the driver automatically generate _id values to ensure uniqueness. Duplicate _id values violate unique index constraints, which causes the driver to return an error.
Update Operations
To update a document, create an instance of UpdateOne and pass in the following arguments:
namespace: The namespace in which to perform the update. This argument is optional if you perform the bulk operation on a single collection.filter: The query filter that specifies the criteria used to match documents in your collection.update: The update you want to perform. For more information about update operations, see the Field Update Operators guide in the MongoDB Server manual.
UpdateOne updates the first document that matches your query filter.
The following example creates an instance of UpdateOne:
operation = UpdateOne( namespace="sample_restaurants.restaurants", filter={ "name": "Mongo's Deli" }, update={ "$set": { "cuisine": "Sandwiches and Salads" }} )
To update multiple documents, create an instance of UpdateMany and pass in the same arguments. UpdateMany updates all documents that match your query filter.
The following example creates an instance of UpdateMany:
operation = UpdateMany( namespace="sample_restaurants.restaurants", filter={ "name": "Mongo's Deli" }, update={ "$set": { "cuisine": "Sandwiches and Salads" }} )
Replace Operations
A replace operation removes all fields and values of a specified document and replaces them with new ones. To perform a replace operation, create an instance of ReplaceOne and pass in the following arguments:
namespace: The namespace in which to perform the replace operation. This argument is optional if you perform the bulk operation on a single collection.filter: The query filter that specifies the criteria used to match the document to replace.replacement: The document that includes the new fields and values you want to store in the matching document.
The following example creates an instance of ReplaceOne:
operation = ReplaceOne( namespace="sample_restaurants.restaurants", filter={ "restaurant_id": "1234" }, replacement={ "name": "Mongo's Pizza", "cuisine": "Pizza", "borough": "Brooklyn", "restaurant_id": "5678" } )
You can also create an instance of ReplaceOne by passing an instance of a custom class to the constructor. This provides additional type safety if you're using a type-checking tool. The instance you pass must inherit from the TypedDict class.
Note
TypedDict in Python 3.7 and Earlier
The TypedDict class is in the typing module, which is available only in Python 3.8 and later. To use the TypedDict class in earlier versions of Python, install the typing_extensions package.
The following example constructs a ReplaceOne instance by using a custom class for added type safety:
class Restaurant (TypedDict): name: str cuisine: str borough: str restaurant_id: str operation = pymongo.ReplaceOne( { "restaurant_id": "1234" }, Restaurant(name="Mongo's Pizza", cuisine="Pizza", borough="Brooklyn", restaurant_id="5678") )
To replace multiple documents, you must create an instance of ReplaceOne for each document.
Tip
Type-Checking Tools
To learn more about type-checking tools available for Python, see Type Checkers on the Tools page.
Delete Operations
To delete a document, create an instance of DeleteOne and pass in the following arguments:
namespace: The namespace in which to delete the document. This argument is optional if you perform the bulk operation on a single collection.filter: The query filter that specifies the criteria used to match the document to delete.
DeleteOne removes only the first document that matches your query filter.
The following example creates an instance of DeleteOne:
operation = DeleteOne( namespace="sample_restaurants.restaurants", filter={ "restaurant_id": "5678" } )
To delete multiple documents, create an instance of DeleteMany and pass in a namespace and query filter specifying the document you want to delete. DeleteMany removes all documents that match your query filter.
The following example creates an instance of DeleteMany:
operation = DeleteMany( namespace="sample_restaurants.restaurants", filter={ "name": "Mongo's Deli" } )
Call the bulk_write() Method
After you define a class instance for each operation you want to perform, pass a list of these instances to the bulk_write() method. Call the bulk_write() method on a Collection instance to write to a single collection or a MongoClient instance to write to multiple namespaces.
If any of the write operations called on a Collection fail, PyMongo raises a BulkWriteError and does not perform any further operations. BulkWriteError provides a details attribute that includes the operation that failed, and details about the exception.
If any of the write operations called on a MongoClient fail, PyMongo raises a ClientBulkWriteException and does not perform any further operations. ClientBulkWriteException provides an error attribute that includes information about the exception.
Note
When PyMongo runs a bulk operation, it uses the write_concern of the collection or client on which the operation is running. You can also set a write concern for the operation when using the MongoClient.bulk_write() method. The driver reports all write concern errors after attempting all operations, regardless of execution order.
To learn more about write concerns, see Write Concern in the MongoDB Server manual.
Collection Bulk Write Example
The following example performs multiple write operations on the restaurants collection by using the bulk_write() method on a Collection instance. Select the Synchronous or Asynchronous tab to see the corresponding code:
operations = [ InsertOne( document={ "name": "Mongo's Deli", "cuisine": "Sandwiches", "borough": "Manhattan", "restaurant_id": "1234" } ), InsertOne( document={ "name": "Mongo's Deli", "cuisine": "Sandwiches", "borough": "Brooklyn", "restaurant_id": "5678" } ), UpdateMany( filter={ "name": "Mongo's Deli" }, update={ "$set": { "cuisine": "Sandwiches and Salads" }} ), DeleteOne( filter={ "restaurant_id": "1234" } ) ] results = restaurants.bulk_write(operations) print(results)
BulkWriteResult({'writeErrors': [], 'writeConcernErrors': [], 'nInserted': 2, 'nUpserted': 0, 'nMatched': 2, 'nModified': 2, 'nRemoved': 1, 'upserted': []}, acknowledged=True)
operations = [ InsertOne( document={ "name": "Mongo's Deli", "cuisine": "Sandwiches", "borough": "Manhattan", "restaurant_id": "1234" } ), InsertOne( document={ "name": "Mongo's Deli", "cuisine": "Sandwiches", "borough": "Brooklyn", "restaurant_id": "5678" } ), UpdateMany( filter={ "name": "Mongo's Deli" }, update={ "$set": { "cuisine": "Sandwiches and Salads" }} ), DeleteOne( filter={ "restaurant_id": "1234" } ) ] results = await restaurants.bulk_write(operations) print(results)
BulkWriteResult({'writeErrors': [], 'writeConcernErrors': [], 'nInserted': 2, 'nUpserted': 0, 'nMatched': 2, 'nModified': 2, 'nRemoved': 1, 'upserted': []}, acknowledged=True)
Client Bulk Write Example
The following example performs multiple write operations on the sample_restaurants.restaurants and sample_mflix.movies namespaces by using the bulk_write() method on a MongoClient instance. Select the Synchronous or Asynchronous tab to see the corresponding code:
operations = [ InsertOne( namespace="sample_mflix.movies", document={ "title": "Minari", "runtime": 217, "genres": ["Drama", "Comedy"] } ), UpdateOne( namespace="sample_mflix.movies", filter={ "title": "Minari" }, update={ "$set": { "runtime": 117 }} ), DeleteMany( namespace="sample_restaurants.restaurants", filter={ "cuisine": "French" } ) ] results = client.bulk_write(operations) print(results)
ClientBulkWriteResult({'anySuccessful': True, 'error': None, 'writeErrors': [], 'writeConcernErrors': [], 'nInserted': 1, 'nUpserted': 0, 'nMatched': 1, 'nModified': 1, 'nDeleted': 344, 'insertResults': {}, 'updateResults': {}, 'deleteResults': {}}, acknowledged=True, verbose=False)
operations = [ InsertOne( namespace="sample_mflix.movies", document={ "title": "Minari", "runtime": 217, "genres": ["Drama", "Comedy"] } ), UpdateOne( namespace="sample_mflix.movies", filter={ "title": "Minari" }, update={ "$set": { "runtime": 117 }} ), DeleteMany( namespace="sample_restaurants.restaurants", filter={ "cuisine": "French" } ) ] results = await client.bulk_write(operations) print(results)
ClientBulkWriteResult({'anySuccessful': True, 'error': None, 'writeErrors': [], 'writeConcernErrors': [], 'nInserted': 1, 'nUpserted': 0, 'nMatched': 1, 'nModified': 1, 'nDeleted': 344, 'insertResults': {}, 'updateResults': {}, 'deleteResults': {}}, acknowledged=True, verbose=False)
Customize Bulk Write Operations
The bulk_write() method optionally accepts additional parameters, which represent options you can use to configure the bulk write operation.
Collection Bulk Write Options
The following table describes the options you can pass to the Collection.bulk_write() method:
Property | Description |
|---|---|
| If |
| Specifies whether the operation bypasses document-level validation. For more
information, see Schema
Validation in the MongoDB
Server manual. |
| An instance of |
| A comment to attach to the operation. For more information, see the delete command fields guide in the MongoDB Server manual. |
| A map of parameter names and values. Values must be constant or closed expressions that don't reference document fields. For more information, see the let statement in the MongoDB Server manual. |
The following example calls the bulk_write() method from the preceding Collection Bulk Write Example but sets the ordered option to False. Select the Synchronous or Asynchronous tab to see the corresponding code:
results = restaurants.bulk_write(operations, ordered=False)
results = await restaurants.bulk_write(operations, ordered=False)
If any of the write operations in an unordered bulk write fail, PyMongo reports the errors only after attempting all operations.
Note
Unordered bulk operations do not guarantee order of execution. The order can differ from the way you list them to optimize the runtime.
Client Bulk Write Options
The following table describes the options you can pass to the MongoClient.bulk_write() method:
Property | Description |
|---|---|
| An instance of |
| If |
| Specifies whether the operation returns detailed results for each
successful operation. |
| Specifies whether the operation bypasses document-level validation. For more
information, see Schema
Validation in the MongoDB
Server manual. |
| A comment to attach to the operation. For more information, see the delete command fields guide in the MongoDB Server manual. |
| A map of parameter names and values. Values must be constant or closed expressions that don't reference document fields. For more information, see the let statement in the MongoDB Server manual. |
| Specifies the write concern to use for the bulk operation. For more information, see Write Concern in the MongoDB Server manual. |
The following example calls the bulk_write() method from the preceding Client Bulk Write Example but sets the verbose_results option to True. Select the Synchronous or Asynchronous tab to see the corresponding code:
results = client.bulk_write(operations, verbose_results=True)
ClientBulkWriteResult({'anySuccessful': True, 'error': None, 'writeErrors': [], 'writeConcernErrors': [], 'nInserted': 1, 'nUpserted': 0, 'nMatched': 1, 'nModified': 1, 'nDeleted': 344, 'insertResults': {0: InsertOneResult(ObjectId('...'), acknowledged=True)}, 'updateResults': {1: UpdateResult({'ok': 1.0, 'idx': 1, 'n': 1, 'nModified': 1}, acknowledged=True)}, 'deleteResults': {2: DeleteResult({'ok': 1.0, 'idx': 2, 'n': 344}, acknowledged=True)}}, acknowledged=True, verbose=True)
results = await client.bulk_write(operations, verbose_results=True)
ClientBulkWriteResult({'anySuccessful': True, 'error': None, 'writeErrors': [], 'writeConcernErrors': [], 'nInserted': 1, 'nUpserted': 0, 'nMatched': 1, 'nModified': 1, 'nDeleted': 344, 'insertResults': {0: InsertOneResult(ObjectId('...'), acknowledged=True)}, 'updateResults': {1: UpdateResult({'ok': 1.0, 'idx': 1, 'n': 1, 'nModified': 1}, acknowledged=True)}, 'deleteResults': {2: DeleteResult({'ok': 1.0, 'idx': 2, 'n': 344}, acknowledged=True)}}, acknowledged=True, verbose=True)
Return Values
This section describes the return value of the following bulk operation methods:
Collection Bulk Write Return Value
The Collection.bulk_write() method returns a BulkWriteResult object. The BulkWriteResult object contains the following properties:
Property | Description |
|---|---|
| Indicates if the server acknowledged the write operation. |
| The raw bulk API result returned by the server. |
| The number of documents deleted, if any. |
| The number of documents inserted, if any. |
| The number of documents matched for an update, if applicable. |
| The number of documents modified, if any. |
| The number of documents upserted, if any. |
| A map of the operation's index to the |
Client Bulk Write Return Value
The MongoClient.bulk_write() method returns a ClientBulkWriteResult object. The ClientBulkWriteResult object contains the following properties:
Property | Description |
|---|---|
| Indicates if the server acknowledged the write operation. |
| The raw bulk API result returned by the server. |
| A map of any successful delete operations and their results. |
| The number of documents deleted, if any. |
| Indicates whether the returned results are verbose. |
| A map of any successful insert operations and their results. |
| The number of documents inserted, if any. |
| The number of documents matched for an update, if applicable. |
| The number of documents modified, if any. |
| A map of any successful update operations and their results. |
| The number of documents upserted, if any. |
Troubleshooting
Client Type Annotations
If you don't add a type annotation for your MongoClient object, your type checker might show an error similar to the following:
from pymongo import MongoClient client = MongoClient() # error: Need type annotation for "client"
The solution is to annotate the MongoClient object as client: MongoClient or client: MongoClient[Dict[str, Any]].
Incompatible Type
If you specify MongoClient as a type hint but don't include data types for the document, keys, and values, your type checker might show an error similar to the following:
error: Dict entry 0 has incompatible type "str": "int"; expected "Mapping[str, Any]": "int"
The solution is to add the following type hint to your MongoClient object:
client: MongoClient[Dict[str, Any]]
Additional Information
To learn how to perform individual write operations, see the following guides:
API Documentation
To learn more about any of the methods or types discussed in this guide, see the following API Documentation: