In this guide, you can learn how to use PyMongo to remove documents from a MongoDB collection by performing delete operations.
A delete operation removes one or more documents from a MongoDB collection. You can perform a delete operation by using the delete_one() or delete_many() methods.
The examples in this guide use the sample_restaurants.restaurants collection 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.
You can perform delete operations in MongoDB by using the following methods:
delete_one(), which deletes the first document that matches the search criteria
delete_many(), which deletes all documents that match the search criteria
Each delete method requires a query filter document, which specifies the search criteria that determine which documents to select for removal. For more information about query filters, see the Query Filter Documents section in the MongoDB Server manual.
The following example uses the delete_one() method to remove a document in the restaurants collection with a name value of "Ready Penny Inn". Select the Synchronous or Asynchronous tab to see the corresponding code:
query_filter = { "name": "Ready Penny Inn" }result = restaurants.delete_one(query_filter)query_filter = { "name": "Ready Penny Inn" }result = await restaurants.delete_one(query_filter)The following example uses the delete_many() method to remove all documents in the restaurants collection with a borough value of "Brooklyn". Select the Synchronous or Asynchronous tab to see the corresponding code:
query_filter = { "borough": "Brooklyn" }result = restaurants.delete_many(query_filter)query_filter = { "borough": "Brooklyn" }result = await restaurants.delete_many(query_filter)The delete_one() and delete_many() methods optionally accept additional parameters, which represent options you can use to configure the delete operation. If you don't specify any additional options, the driver does not customize the delete operation.
Property
Description
collation
Specifies the kind of language collation to use when sorting results. See
Collationfor more information.
hint
Gets or sets the index to scan for documents. For more information, see the
hint statementin the MongoDB Server manual.
session
An instance of ClientSession.
let
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 statementin the MongoDB Server manual.
comment
A comment to attach to the operation. For more information, see the
delete command fieldsguide in the MongoDB Server manual for more information.
The following code uses the delete_many() method to delete all documents in the restaurants collection with a name value that includes the string "Mongo". It also uses the comment option to add a comment to the operation. Select the Synchronous or Asynchronous tab to see the corresponding code:
query_filter = { 'name': {'$regex': 'Mongo' }}result = restaurants.delete_many(query_filter, comment="Deleting Mongo restaurants")query_filter = { 'name': {'$regex': 'Mongo' }}result = await restaurants.delete_many(query_filter, comment="Deleting Mongo restaurants")If the preceding example used the delete_one() method instead of delete_many(), the driver would delete only the first document with a name value that includes "Mongo".
When you perform a delete operation, you can specify a collation for the driver to use.
A collation is a set of language-specific rules for string comparison, such as for letter case and accent marks.
To specify a collation, create an instance of the Collation class or a Python dictionary. For a list of options to pass to the Collation constructor or include as keys in the dictionary, see Collation in the MongoDB Server manual.
To create an instance of the Collation class, you must import it from pymongo.collation.
The following example performs the same delete operation as the previous example, but with a default collation of fr_CA. Select the Synchronous or Asynchronous tab to see the corresponding code:
from pymongo.collation import Collationquery_filter = { "borough": "Brooklyn" }result = restaurants.delete_many(query_filter, collation=Collation(locale='fr_CA'))from pymongo.collation import Collationquery_filter = { "borough": "Brooklyn" }result = await restaurants.delete_many(query_filter, collation=Collation(locale='fr_CA'))When you specify a collation as part of an operation, it overrides the default collation for the collection.
The delete_one() and delete_many() methods return a DeleteResult type. This type contains the following properties:
deleted_count, which indicates the number of documents deleted
acknowledged, which indicates if the server acknowledges the result
raw_result, which is the raw result returned by the server
If the acknowledged attribute is False, all other attributes of DeleteResult raise an InvalidOperation exception when accessed. The driver cannot determine these values if the server does not acknowledge the write operation.
If the query filter does not match any documents, the driver doesn't delete any documents and deleted_count is 0.
To learn more about any of the methods or types discussed in this guide, see the following API Documentation:
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