MotorCollection

class motor.motor_tornado.MotorCollection(database, name, codec_options=None, read_preference=None, write_concern=None, read_concern=None, _delegate=None)
c[name] || c.name

Get the name sub-collection of MotorCollection c.

Raises InvalidName if an invalid collection name is used.

database

The MotorDatabase that this MotorCollection is a part of.

coroutine create_index(self, keys, **kwargs)

Creates an index on this collection.

Takes either a single key or a list of (key, direction) pairs. The key(s) must be an instance of basestring (str in python 3), and the direction(s) must be one of (ASCENDING, DESCENDING, GEO2D, GEOHAYSTACK, GEOSPHERE, HASHED, TEXT).

To create a single key ascending index on the key 'mike' we just use a string argument:

yield my_collection.create_index("mike")

For a compound index on 'mike' descending and 'eliot' ascending we need to use a list of tuples:

yield my_collection.create_index([("mike", pymongo.DESCENDING),
                                  ("eliot", pymongo.ASCENDING)])

All optional index creation parameters should be passed as keyword arguments to this method. For example:

yield my_collection.create_index([("mike", pymongo.DESCENDING)],
                                 background=True)

Valid options include, but are not limited to:

  • name: custom name to use for this index - if none is given, a name will be generated.
  • unique: if True creates a uniqueness constraint on the index.
  • background: if True this index should be created in the background.
  • sparse: if True, omit from the index any documents that lack the indexed field.
  • bucketSize: for use with geoHaystack indexes. Number of documents to group together within a certain proximity to a given longitude and latitude.
  • min: minimum value for keys in a GEO2D index.
  • max: maximum value for keys in a GEO2D index.
  • expireAfterSeconds: <int> Used to create an expiring (TTL) collection. MongoDB will automatically delete documents from this collection after <int> seconds. The indexed field must be a UTC datetime or the data will not expire.
  • partialFilterExpression: A document that specifies a filter for a partial index.
  • collation (optional): An instance of Collation. This option is only supported on MongoDB 3.4 and above.

See the MongoDB documentation for a full list of supported options by server version.

Warning

dropDups is not supported by MongoDB 3.0 or newer. The option is silently ignored by the server and unique index builds using the option will fail if a duplicate value is detected.

Note

partialFilterExpression requires server version >= 3.2

Note

The write_concern of this collection is automatically applied to this operation when using MongoDB >= 3.4.

Parameters:
  • keys: a single key or a list of (key, direction) pairs specifying the index to create
  • **kwargs (optional): any additional index creation options (see the above list) should be passed as keyword arguments

Returns a Future.

See also

The MongoDB documentation on

indexes

coroutine inline_map_reduce(self, map, reduce, full_response=False, **kwargs)

Perform an inline map/reduce operation on this collection.

Perform the map/reduce operation on the server in RAM. A result collection is not created. The result set is returned as a list of documents.

If full_response is False (default) returns the result documents in a list. Otherwise, returns the full response from the server to the map reduce command.

The inline_map_reduce() method obeys the read_preference of this Collection.

Parameters:
  • map: map function (as a JavaScript string)

  • reduce: reduce function (as a JavaScript string)

  • full_response (optional): if True, return full response to this command - otherwise just return the result collection

  • **kwargs (optional): additional arguments to the map reduce command may be passed as keyword arguments to this helper method, e.g.:

    yield db.test.inline_map_reduce(map, reduce, limit=2)
    

Returns a Future.

See also

The MongoDB documentation on

mapreduce

aggregate(pipeline, **kwargs)

Execute an aggregation pipeline on this collection.

The aggregation can be run on a secondary if the client is connected to a replica set and its read_preference is not PRIMARY.

Parameters:
  • pipeline: a single command or list of aggregation commands
  • session (optional): a ClientSession, created with start_session().
  • **kwargs: send arbitrary parameters to the aggregate command

Returns a MotorCommandCursor that can be iterated like a cursor from find():

pipeline = [{'$project': {'name': {'$toUpper': '$name'}}}]
cursor = collection.aggregate(pipeline)
while (yield cursor.fetch_next):
    doc = cursor.next_object()
    print(doc)

In Python 3.5 and newer, aggregation cursors can be iterated elegantly in native coroutines with async for:

async def f():
    async for doc in collection.aggregate(pipeline):
        print(doc)

MotorCommandCursor does not allow the explain option. To explain MongoDB’s query plan for the aggregation, use MotorDatabase.command():

async def f():
    plan = await db.command(
        'aggregate', 'COLLECTION-NAME',
        pipeline=[{'$project': {'x': 1}}],
        explain=True)

    print(plan)

Changed in version 1.0: aggregate() now always returns a cursor.

Changed in version 0.5: aggregate() now returns a cursor by default, and the cursor is returned immediately without a yield. See aggregation changes in Motor 0.5.

Changed in version 0.2: Added cursor support.

aggregate_raw_batches(pipeline, **kwargs)

Perform an aggregation and retrieve batches of raw BSON.

Similar to the aggregate() method but returns each batch as bytes.

This example demonstrates how to work with raw batches, but in practice raw batches should be passed to an external library that can decode BSON into another data type, rather than used with PyMongo’s bson module.

async def get_raw():
    cursor = db.test.aggregate_raw_batches()
    async for batch in cursor:
        print(bson.decode_all(batch))

Note that aggregate_raw_batches does not support sessions.

New in version 2.0.

coroutine bulk_write(requests, ordered=True, bypass_document_validation=False, session=None)

Send a batch of write operations to the server.

Requests are passed as a list of write operation instances imported from pymongo: InsertOne, UpdateOne, UpdateMany, ReplaceOne, DeleteOne, or DeleteMany).

For example, say we have these documents:

{'x': 1, '_id': ObjectId('54f62e60fba5226811f634ef')}
{'x': 1, '_id': ObjectId('54f62e60fba5226811f634f0')}

We can insert a document, delete one, and replace one like so:

# DeleteMany, UpdateOne, and UpdateMany are also available.
from pymongo import InsertOne, DeleteOne, ReplaceOne

async def modify_data():
    requests = [InsertOne({'y': 1}), DeleteOne({'x': 1}),
                ReplaceOne({'w': 1}, {'z': 1}, upsert=True)]
    result = await db.test.bulk_write(requests)

    print("inserted %d, deleted %d, modified %d" % (
        result.inserted_count, result.deleted_count, result.modified_count))

    print("upserted_ids: %s" % result.upserted_ids)

    print("collection:")
    async for doc in db.test.find():
        print(doc)

This will print something like:

inserted 1, deleted 1, modified 0
upserted_ids: {2: ObjectId('54f62ee28891e756a6e1abd5')}

collection:
{'x': 1, '_id': ObjectId('54f62e60fba5226811f634f0')}
{'y': 1, '_id': ObjectId('54f62ee2fba5226811f634f1')}
{'z': 1, '_id': ObjectId('54f62ee28891e756a6e1abd5')}
Parameters:
  • requests: A list of write operations (see examples above).
  • ordered (optional): If True (the default) requests will be performed on the server serially, in the order provided. If an error occurs all remaining operations are aborted. If False requests will be performed on the server in arbitrary order, possibly in parallel, and all operations will be attempted.
  • bypass_document_validation: (optional) If True, allows the write to opt-out of document level validation. Default is False.
  • session (optional): a ClientSession, created with start_session().
Returns:

An instance of BulkWriteResult.

Note

bypass_document_validation requires server version >= 3.2

Changed in version 1.2: Added session parameter.

coroutine count_documents(filter, session=None, **kwargs)

Count the number of documents in this collection.

The count_documents() method is supported in a transaction.

All optional parameters should be passed as keyword arguments to this method. Valid options include:

  • skip (int): The number of matching documents to skip before returning results.
  • limit (int): The maximum number of documents to count.
  • maxTimeMS (int): The maximum amount of time to allow this operation to run, in milliseconds.
  • collation (optional): An instance of Collation. This option is only supported on MongoDB 3.4 and above.
  • hint (string or list of tuples): The index to use. Specify either the index name as a string or the index specification as a list of tuples (e.g. [(‘a’, pymongo.ASCENDING), (‘b’, pymongo.ASCENDING)]). This option is only supported on MongoDB 3.6 and above.

The count_documents() method obeys the read_preference of this Collection.

Note

When migrating from count() to count_documents() the following query operators must be replaced:

Operator Replacement
$where $expr
$near $geoWithin with $center
$nearSphere $geoWithin with $centerSphere

$expr requires MongoDB 3.6+

Parameters:
  • filter (required): A query document that selects which documents to count in the collection. Can be an empty document to count all documents.
  • session (optional): a ClientSession.
  • **kwargs (optional): See list of options above.
coroutine create_indexes(indexes, session=None, **kwargs)

Create one or more indexes on this collection:

from pymongo import IndexModel, ASCENDING, DESCENDING

async def create_two_indexes():
    index1 = IndexModel([("hello", DESCENDING),
                         ("world", ASCENDING)], name="hello_world")
    index2 = IndexModel([("goodbye", DESCENDING)])
    print(await db.test.create_indexes([index1, index2]))

This prints:

['hello_world', 'goodbye_-1']
Parameters:
  • indexes: A list of IndexModel instances.
  • session (optional): a ClientSession, created with start_session().
  • **kwargs (optional): optional arguments to the createIndexes command (like maxTimeMS) can be passed as keyword arguments.

The write_concern of this collection is automatically applied to this operation when using MongoDB >= 3.4.

Changed in version 1.2: Added session parameter.

coroutine delete_many(filter, collation=None, session=None)

Delete one or more documents matching the filter.

If we have a collection with 3 documents like {'x': 1}, then:

async def clear_collection():
    result = await db.test.delete_many({'x': 1})
    print(result.deleted_count)

This deletes all matching documents and prints “3”.

Parameters:
  • filter: A query that matches the documents to delete.
  • collation (optional): An instance of Collation. This option is only supported on MongoDB 3.4 and above.
  • session (optional): a ClientSession, created with start_session().
Returns:

Changed in version 1.2: Added session parameter.

coroutine delete_one(filter, collation=None, session=None)

Delete a single document matching the filter.

If we have a collection with 3 documents like {'x': 1}, then:

async def clear_collection():
    result = await db.test.delete_one({'x': 1})
    print(result.deleted_count)

This deletes one matching document and prints “1”.

Parameters:
  • filter: A query that matches the document to delete.
  • collation (optional): An instance of Collation. This option is only supported on MongoDB 3.4 and above.
  • session (optional): a ClientSession, created with start_session().
Returns:

Changed in version 1.2: Added session parameter.

coroutine distinct(key, filter=None, session=None, **kwargs)

Get a list of distinct values for key among all documents in this collection.

Raises TypeError if key is not an instance of basestring (str in python 3).

All optional distinct parameters should be passed as keyword arguments to this method. Valid options include:

  • maxTimeMS (int): The maximum amount of time to allow the count command to run, in milliseconds.
  • collation (optional): An instance of Collation. This option is only supported on MongoDB 3.4 and above.

The distinct() method obeys the read_preference of this Collection.

Parameters:
  • key: name of the field for which we want to get the distinct values
  • filter (optional): A query document that specifies the documents from which to retrieve the distinct values.
  • session (optional): a ClientSession.
  • **kwargs (optional): See list of options above.
coroutine drop(session=None)

Alias for drop_collection.

The following two calls are equivalent:

await db.foo.drop()
await db.drop_collection("foo")
coroutine drop_index(index_or_name, session=None, **kwargs)

Drops the specified index on this collection.

Can be used on non-existant collections or collections with no indexes. Raises OperationFailure on an error (e.g. trying to drop an index that does not exist). index_or_name can be either an index name (as returned by create_index), or an index specifier (as passed to create_index). An index specifier should be a list of (key, direction) pairs. Raises TypeError if index is not an instance of (str, unicode, list).

Warning

if a custom name was used on index creation (by passing the name parameter to create_index() or ensure_index()) the index must be dropped by name.

Parameters:
  • index_or_name: index (or name of index) to drop
  • session (optional): a ClientSession.
  • **kwargs (optional): optional arguments to the createIndexes command (like maxTimeMS) can be passed as keyword arguments.

Note

The write_concern of this collection is automatically applied to this operation when using MongoDB >= 3.4.

coroutine drop_indexes(session=None, **kwargs)

Drops all indexes on this collection.

Can be used on non-existant collections or collections with no indexes. Raises OperationFailure on an error.

Parameters:
  • session (optional): a ClientSession.
  • **kwargs (optional): optional arguments to the createIndexes command (like maxTimeMS) can be passed as keyword arguments.

Note

The write_concern of this collection is automatically applied to this operation when using MongoDB >= 3.4.

coroutine estimated_document_count(**kwargs)

Get an estimate of the number of documents in this collection using collection metadata.

The estimated_document_count() method is not supported in a transaction.

All optional parameters should be passed as keyword arguments to this method. Valid options include:

  • maxTimeMS (int): The maximum amount of time to allow this operation to run, in milliseconds.
Parameters:
  • **kwargs (optional): See list of options above.
find(*args, **kwargs)

Create a MotorCursor. Same parameters as for PyMongo’s find().

Note that find does not require an await expression, because find merely creates a MotorCursor without performing any operations on the server. MotorCursor methods such as to_list() perform actual operations.

coroutine find_one(filter=None, *args, **kwargs)

Get a single document from the database.

All arguments to find() are also valid arguments for find_one(), although any limit argument will be ignored. Returns a single document, or None if no matching document is found.

The find_one() method obeys the read_preference of this Motor collection instance.

Parameters:
  • filter (optional): a dictionary specifying the query to be performed OR any other type to be used as the value for a query for "_id".
  • *args (optional): any additional positional arguments are the same as the arguments to find().
  • **kwargs (optional): any additional keyword arguments are the same as the arguments to find().
  • max_time_ms (optional): a value for max_time_ms may be specified as part of **kwargs, e.g.:
await collection.find_one(max_time_ms=100)

Changed in version 1.2: Added session parameter.

coroutine find_one_and_delete(filter, projection=None, sort=None, session=None, **kwargs)

Finds a single document and deletes it, returning the document.

If we have a collection with 2 documents like {'x': 1}, then this code retrieves and deletes one of them:

async def delete_one_document():
    print(await db.test.count_documents({'x': 1}))
    doc = await db.test.find_one_and_delete({'x': 1})
    print(doc)
    print(await db.test.count_documents({'x': 1}))

This outputs something like:

2
{'x': 1, '_id': ObjectId('54f4e12bfba5220aa4d6dee8')}
1

If multiple documents match filter, a sort can be applied. Say we have 3 documents like:

{'x': 1, '_id': 0}
{'x': 1, '_id': 1}
{'x': 1, '_id': 2}

This code retrieves and deletes the document with the largest _id:

async def delete_with_largest_id():
    doc = await db.test.find_one_and_delete(
        {'x': 1}, sort=[('_id', pymongo.DESCENDING)])

This deletes one document and prints it:

{'x': 1, '_id': 2}

The projection option can be used to limit the fields returned:

async def delete_and_return_x():
    db.test.find_one_and_delete({'x': 1}, projection={'_id': False})

This prints:

{'x': 1}
Parameters:
  • filter: A query that matches the document to delete.
  • projection (optional): a list of field names that should be returned in the result document or a mapping specifying the fields to include or exclude. If projection is a list “_id” will always be returned. Use a mapping to exclude fields from the result (e.g. projection={‘_id’: False}).
  • sort (optional): a list of (key, direction) pairs specifying the sort order for the query. If multiple documents match the query, they are sorted and the first is deleted.
  • session (optional): a ClientSession, created with start_session().
  • **kwargs (optional): additional command arguments can be passed as keyword arguments (for example maxTimeMS can be used with recent server versions).

This command uses the WriteConcern of this Collection when connected to MongoDB >= 3.2. Note that using an elevated write concern with this command may be slower compared to using the default write concern.

Changed in version 1.2: Added session parameter.

coroutine find_one_and_replace(filter, replacement, projection=None, sort=None, upsert=False, return_document=False, session=None, **kwargs)

Finds a single document and replaces it, returning either the original or the replaced document.

The find_one_and_replace() method differs from find_one_and_update() by replacing the document matched by filter, rather than modifying the existing document.

Say we have 3 documents like:

{'x': 1, '_id': 0}
{'x': 1, '_id': 1}
{'x': 1, '_id': 2}

Replace one of them like so:

async def replace_one_doc():
    original_doc = await db.test.find_one_and_replace({'x': 1}, {'y': 1})
    print("original: %s" % original_doc)
    print("collection:")
    async for doc in db.test.find():
        print(doc)

This will print:

original: {'x': 1, '_id': 0}
collection:
{'y': 1, '_id': 0}
{'x': 1, '_id': 1}
{'x': 1, '_id': 2}
Parameters:
  • filter: A query that matches the document to replace.
  • replacement: The replacement document.
  • projection (optional): A list of field names that should be returned in the result document or a mapping specifying the fields to include or exclude. If projection is a list “_id” will always be returned. Use a mapping to exclude fields from the result (e.g. projection={‘_id’: False}).
  • sort (optional): a list of (key, direction) pairs specifying the sort order for the query. If multiple documents match the query, they are sorted and the first is replaced.
  • upsert (optional): When True, inserts a new document if no document matches the query. Defaults to False.
  • return_document: If ReturnDocument.BEFORE (the default), returns the original document before it was replaced, or None if no document matches. If ReturnDocument.AFTER, returns the replaced or inserted document.
  • session (optional): a ClientSession, created with start_session().
  • **kwargs (optional): additional command arguments can be passed as keyword arguments (for example maxTimeMS can be used with recent server versions).

This command uses the WriteConcern of this Collection when connected to MongoDB >= 3.2. Note that using an elevated write concern with this command may be slower compared to using the default write concern.

Changed in version 1.2: Added session parameter.

coroutine find_one_and_update(filter, update, projection=None, sort=None, upsert=False, return_document=False, array_filters=None, session=None, **kwargs)

Finds a single document and updates it, returning either the original or the updated document. By default find_one_and_update() returns the original version of the document before the update was applied:

async def set_done():
    print(await db.test.find_one_and_update(
        {'_id': 665}, {'$inc': {'count': 1}, '$set': {'done': True}}))

This outputs:

{'_id': 665, 'done': False, 'count': 25}}

To return the updated version of the document instead, use the return_document option.

from pymongo import ReturnDocument

async def increment_by_userid():
    print(await db.example.find_one_and_update(
        {'_id': 'userid'},
        {'$inc': {'seq': 1}},
        return_document=ReturnDocument.AFTER))

This prints:

{'_id': 'userid', 'seq': 1}

You can limit the fields returned with the projection option.

async def increment_by_userid():
    print(await db.example.find_one_and_update(
        {'_id': 'userid'},
        {'$inc': {'seq': 1}},
        projection={'seq': True, '_id': False},
        return_document=ReturnDocument.AFTER))

This results in:

{'seq': 2}

The upsert option can be used to create the document if it doesn’t already exist.

async def increment_by_userid():
    print(await db.example.find_one_and_update(
        {'_id': 'userid'},
        {'$inc': {'seq': 1}},
        projection={'seq': True, '_id': False},
        upsert=True,
        return_document=ReturnDocument.AFTER))

The result:

{'seq': 1}

If multiple documents match filter, a sort can be applied. Say we have these two documents:

{'_id': 665, 'done': True, 'result': {'count': 26}}
{'_id': 701, 'done': True, 'result': {'count': 17}}

Then to update the one with the great _id:

async def set_done():
    print(await db.test.find_one_and_update(
        {'done': True},
        {'$set': {'final': True}},
        sort=[('_id', pymongo.DESCENDING)]))

This would print:

{'_id': 701, 'done': True, 'result': {'count': 17}}
Parameters:
  • filter: A query that matches the document to update.
  • update: The update operations to apply.
  • projection (optional): A list of field names that should be returned in the result document or a mapping specifying the fields to include or exclude. If projection is a list “_id” will always be returned. Use a dict to exclude fields from the result (e.g. projection={‘_id’: False}).
  • sort (optional): a list of (key, direction) pairs specifying the sort order for the query. If multiple documents match the query, they are sorted and the first is updated.
  • upsert (optional): When True, inserts a new document if no document matches the query. Defaults to False.
  • return_document: If ReturnDocument.BEFORE (the default), returns the original document before it was updated, or None if no document matches. If ReturnDocument.AFTER, returns the updated or inserted document.
  • array_filters (optional): A list of filters specifying which array elements an update should apply. Requires MongoDB 3.6+.
  • session (optional): a ClientSession, created with start_session().
  • **kwargs (optional): additional command arguments can be passed as keyword arguments (for example maxTimeMS can be used with recent server versions).

This command uses the WriteConcern of this Collection when connected to MongoDB >= 3.2. Note that using an elevated write concern with this command may be slower compared to using the default write concern.

Changed in version 1.2: Added array_filters and session parameters.

find_raw_batches(*args, **kwargs)

Query the database and retrieve batches of raw BSON.

Similar to the find() method but returns each batch as bytes.

This example demonstrates how to work with raw batches, but in practice raw batches should be passed to an external library that can decode BSON into another data type, rather than used with PyMongo’s bson module.

async def get_raw():
    cursor = db.test.find_raw_batches()
    async for batch in cursor:
        print(bson.decode_all(batch))

Note that find_raw_batches does not support sessions.

New in version 2.0.

coroutine index_information(session=None)

Get information on this collection’s indexes.

Returns a dictionary where the keys are index names (as returned by create_index()) and the values are dictionaries containing information about each index. The dictionary is guaranteed to contain at least a single key, "key" which is a list of (key, direction) pairs specifying the index (as passed to create_index()). It will also contain any other metadata about the indexes, except for the "ns" and "name" keys, which are cleaned. For example:

async def create_x_index():
    print(await db.test.create_index("x", unique=True))
    print(await db.test.index_information())

This prints:

'x_1'
{'_id_': {'key': [('_id', 1)]},
 'x_1': {'unique': True, 'key': [('x', 1)]}}

Changed in version 1.2: Added session parameter.

coroutine insert_many(documents, ordered=True, bypass_document_validation=False, session=None)

Insert an iterable of documents.

async def insert_2_docs():
    result = db.test.insert_many([{'x': i} for i in range(2)])
    result.inserted_ids

This prints something like:

[ObjectId('54f113fffba522406c9cc20e'), ObjectId('54f113fffba522406c9cc20f')]
Parameters:
  • documents: A iterable of documents to insert.
  • ordered (optional): If True (the default) documents will be inserted on the server serially, in the order provided. If an error occurs all remaining inserts are aborted. If False, documents will be inserted on the server in arbitrary order, possibly in parallel, and all document inserts will be attempted.
  • bypass_document_validation: (optional) If True, allows the write to opt-out of document level validation. Default is False.
  • session (optional): a ClientSession, created with start_session().
Returns:

An instance of InsertManyResult.

Note

bypass_document_validation requires server version >= 3.2

Changed in version 1.2: Added session parameter.

coroutine insert_one(document, bypass_document_validation=False, session=None)

Insert a single document.

async def insert_x():
    result = await db.test.insert_one({'x': 1})
    print(result.inserted_id)

This code outputs the new document’s _id:

ObjectId('54f112defba522406c9cc208')
Parameters:
  • document: The document to insert. Must be a mutable mapping type. If the document does not have an _id field one will be added automatically.
  • bypass_document_validation: (optional) If True, allows the write to opt-out of document level validation. Default is False.
  • session (optional): a ClientSession, created with start_session().
Returns:

Note

bypass_document_validation requires server version >= 3.2

Changed in version 1.2: Added session parameter.

list_indexes(session=None)

Get a cursor over the index documents for this collection.

async def print_indexes():
    for index in await db.test.list_indexes():
        print(index)

If the only index is the default index on _id, this might print:

SON([('v', 1), ('key', SON([('_id', 1)])), ('name', '_id_'), ('ns', 'test.test')])
coroutine map_reduce(map, reduce, out, full_response=False, session=None, **kwargs)

Perform a map/reduce operation on this collection.

If full_response is False (default) returns a MotorCollection instance containing the results of the operation. Otherwise, returns the full response from the server to the map reduce command.

Parameters:
  • map: map function (as a JavaScript string)

  • reduce: reduce function (as a JavaScript string)

  • out: output collection name or out object (dict). See the map reduce command documentation for available options. Note: out options are order sensitive. SON can be used to specify multiple options. e.g. SON([(‘replace’, <collection name>), (‘db’, <database name>)])

  • full_response (optional): if True, return full response to this command - otherwise just return the result collection

  • session (optional): a ClientSession, created with start_session().

  • **kwargs (optional): additional arguments to the map reduce command may be passed as keyword arguments to this helper method, e.g.:

    result = yield db.test.map_reduce(map, reduce, "myresults", limit=2)
    

Returns a Future.

Note

The map_reduce() method does not obey the read_preference of this MotorCollection. To run mapReduce on a secondary use the inline_map_reduce() method instead.

See also

The MongoDB documentation on

mapreduce

Changed in version 1.2: Added session parameter.

coroutine options(session=None)

Get the options set on this collection.

Returns a dictionary of options and their values - see create_collection() for more information on the possible options. Returns an empty dictionary if the collection has not been created yet.

Parameters:
coroutine reindex(session=None, **kwargs)

Rebuilds all indexes on this collection.

Parameters:
  • session (optional): a ClientSession.
  • **kwargs (optional): optional arguments to the reIndex command (like maxTimeMS) can be passed as keyword arguments.

Warning

reindex blocks all other operations (indexes are built in the foreground) and will be slow for large collections.

coroutine rename(new_name, session=None, **kwargs)

Rename this collection.

If operating in auth mode, client must be authorized as an admin to perform this operation. Raises TypeError if new_name is not an instance of basestring (str in python 3). Raises InvalidName if new_name is not a valid collection name.

Parameters:
  • new_name: new name for this collection
  • session (optional): a ClientSession.
  • **kwargs (optional): additional arguments to the rename command may be passed as keyword arguments to this helper method (i.e. dropTarget=True)

Note

The write_concern of this collection is automatically applied to this operation when using MongoDB >= 3.4.

coroutine replace_one(filter, replacement, upsert=False, bypass_document_validation=False, collation=None, session=None)

Replace a single document matching the filter.

Say our collection has one document:

{'x': 1, '_id': ObjectId('54f4c5befba5220aa4d6dee7')}

Then to replace it with another:

async def_replace_x_with_y():
    result = await db.test.replace_one({'x': 1}, {'y': 1})
    print('matched %d, modified %d' %
        (result.matched_count, result.modified_count))

    print('collection:')
    async for doc in db.test.find():
        print(doc)

This prints:

matched 1, modified 1
collection:
{'y': 1, '_id': ObjectId('54f4c5befba5220aa4d6dee7')}

The upsert option can be used to insert a new document if a matching document does not exist:

async def_replace_or_upsert():
    result = await db.test.replace_one({'x': 1}, {'x': 1}, True)
    print('matched %d, modified %d, upserted_id %r' %
        (result.matched_count, result.modified_count, result.upserted_id))

    print('collection:')
    async for doc in db.test.find():
        print(doc)

This prints:

matched 1, modified 1, upserted_id ObjectId('54f11e5c8891e756a6e1abd4')
collection:
{'y': 1, '_id': ObjectId('54f4c5befba5220aa4d6dee7')}
Parameters:
  • filter: A query that matches the document to replace.
  • replacement: The new document.
  • upsert (optional): If True, perform an insert if no documents match the filter.
  • bypass_document_validation: (optional) If True, allows the write to opt-out of document level validation. Default is False.
  • collation (optional): An instance of Collation. This option is only supported on MongoDB 3.4 and above.
  • session (optional): a ClientSession, created with start_session().
Returns:

Note

bypass_document_validation requires server version >= 3.2

Changed in version 1.2: Added session parameter.

coroutine update_many(filter, update, upsert=False, array_filters=None, bypass_document_validation=False, collation=None, session=None)

Update one or more documents that match the filter.

Say our collection has 3 documents:

{'x': 1, '_id': 0}
{'x': 1, '_id': 1}
{'x': 1, '_id': 2}

We can add 3 to each “x” field:

async def add_3_to_x():
  result = await db.test.update_many({'x': 1}, {'$inc': {'x': 3}})
  print('matched %d, modified %d' % 
        (result.matched_count, result.modified_count))

  print('collection:')
  async for doc in db.test.find():
      print(doc)

This prints:

matched 3, modified 3
collection:
{'x': 4, '_id': 0}
{'x': 4, '_id': 1}
{'x': 4, '_id': 2}
Parameters:
  • filter: A query that matches the documents to update.
  • update: The modifications to apply.
  • upsert (optional): If True, perform an insert if no documents match the filter.
  • bypass_document_validation (optional): If True, allows the write to opt-out of document level validation. Default is False.
  • collation (optional): An instance of Collation. This option is only supported on MongoDB 3.4 and above.
  • array_filters (optional): A list of filters specifying which array elements an update should apply. Requires MongoDB 3.6+.
  • session (optional): a ClientSession, created with start_session().
Returns:

Note

bypass_document_validation requires server version >= 3.2

Changed in version 1.2: Added array_filters and session parameters.

coroutine update_one(filter, update, upsert=False, bypass_document_validation=False, collation=None, array_filters=None, session=None)

Update a single document matching the filter.

Say our collection has 3 documents:

{'x': 1, '_id': 0}
{'x': 1, '_id': 1}
{'x': 1, '_id': 2}

We can add 3 to the “x” field of one of the documents:

async def add_3_to_x():
  result = await db.test.update_one({'x': 1}, {'$inc': {'x': 3}})
  print('matched %d, modified %d' %
        (result.matched_count, result.modified_count))

  print('collection:')
  async for doc in db.test.find():
      print(doc)

This prints:

matched 1, modified 1
collection:
{'x': 4, '_id': 0}
{'x': 1, '_id': 1}
{'x': 1, '_id': 2}
Parameters:
  • filter: A query that matches the document to update.
  • update: The modifications to apply.
  • upsert (optional): If True, perform an insert if no documents match the filter.
  • bypass_document_validation: (optional) If True, allows the write to opt-out of document level validation. Default is False.
  • collation (optional): An instance of Collation. This option is only supported on MongoDB 3.4 and above.
  • array_filters (optional): A list of filters specifying which array elements an update should apply. Requires MongoDB 3.6+.
  • session (optional): a ClientSession, created with start_session().
Returns:

Note

bypass_document_validation requires server version >= 3.2

Changed in version 1.2: Added array_filters and session parameters.

watch(pipeline=None, full_document='default', resume_after=None, max_await_time_ms=None, batch_size=None, collation=None, start_at_operation_time=None, session=None)

Watch changes on this collection.

Returns a MotorChangeStream cursor which iterates over changes on this collection. Introduced in MongoDB 3.6.

A change stream continues waiting indefinitely for matching change events. Code like the following allows a program to cancel the change stream and exit.

change_stream = None

async def watch_collection():
    global change_stream

    # Using the change stream in an "async with" block
    # ensures it is canceled promptly if your code breaks
    # from the loop or throws an exception.
    async with db.collection.watch() as change_stream:
        async for change in stream:
            print(change)

# Tornado
from tornado.ioloop import IOLoop

def main():
    loop = IOLoop.current()
    # Start watching collection for changes.
    loop.add_callback(watch_collection)
    try:
        loop.start()
    except KeyboardInterrupt:
        pass
    finally:
        if change_stream is not None:
            change_stream.close()

# asyncio
from asyncio import get_event_loop

def main():
    loop = get_event_loop()
    task = loop.create_task(watch_collection)

    try:
        loop.run_forever()
    except KeyboardInterrupt:
        pass
    finally:
        if change_stream is not None:
            change_stream.close()

        # Prevent "Task was destroyed but it is pending!"
        loop.run_until_complete(task)

The MotorChangeStream async iterable blocks until the next change document is returned or an error is raised. If the next() method encounters a network error when retrieving a batch from the server, it will automatically attempt to recreate the cursor such that no change events are missed. Any error encountered during the resume attempt indicates there may be an outage and will be raised.

try:
    pipeline = [{'$match': {'operationType': 'insert'}}]
    async with db.collection.watch(pipeline) as stream:
        async for change in stream:
            print(change)
except pymongo.errors.PyMongoError:
    # The ChangeStream encountered an unrecoverable error or the
    # resume attempt failed to recreate the cursor.
    logging.error('...')

For a precise description of the resume process see the change streams specification.

Parameters:
  • pipeline (optional): A list of aggregation pipeline stages to append to an initial $changeStream stage. Not all pipeline stages are valid after a $changeStream stage, see the MongoDB documentation on change streams for the supported stages.
  • full_document (optional): The fullDocument option to pass to the $changeStream stage. Allowed values: ‘default’, ‘updateLookup’. Defaults to ‘default’. When set to ‘updateLookup’, the change notification for partial updates will include both a delta describing the changes to the document, as well as a copy of the entire document that was changed from some time after the change occurred.
  • resume_after (optional): The logical starting point for this change stream.
  • max_await_time_ms (optional): The maximum time in milliseconds for the server to wait for changes before responding to a getMore operation.
  • batch_size (optional): The maximum number of documents to return per batch.
  • collation (optional): The Collation to use for the aggregation.
  • session (optional): a ClientSession.
Returns:

A MotorChangeStream.

See the Tornado Change Stream Example.

New in version 1.2.

See also

The MongoDB documentation on

changeStreams

with_options(codec_options=None, read_preference=None, write_concern=None, read_concern=None)

Get a clone of this collection changing the specified settings.

>>> coll1.read_preference
Primary()
>>> from pymongo import ReadPreference
>>> coll2 = coll1.with_options(read_preference=ReadPreference.SECONDARY)
>>> coll1.read_preference
Primary()
>>> coll2.read_preference
Secondary(tag_sets=None)
Parameters:
  • codec_options (optional): An instance of CodecOptions. If None (the default) the codec_options of this Collection is used.
  • read_preference (optional): The read preference to use. If None (the default) the read_preference of this Collection is used. See read_preferences for options.
  • write_concern (optional): An instance of WriteConcern. If None (the default) the write_concern of this Collection is used.
  • read_concern (optional): An instance of ReadConcern. If None (the default) the read_concern of this Collection is used.
codec_options

Read only access to the CodecOptions of this instance.

full_name

The full name of this Collection.

The full name is of the form database_name.collection_name.

name

The name of this Collection.

read_concern

Read only access to the ReadConcern of this instance.

New in version 3.2.

read_preference

Read only access to the read preference of this instance.

Changed in version 3.0: The read_preference attribute is now read only.

write_concern

Read only access to the WriteConcern of this instance.

Changed in version 3.0: The write_concern attribute is now read only.