errors – Exceptions raised by the pymongo package

Exceptions raised by PyMongo.

exception pymongo.errors.AutoReconnect(message='', errors=None)

Raised when a connection to the database is lost and an attempt to auto-reconnect will be made.

In order to auto-reconnect you must handle this exception, recognizing that the operation which caused it has not necessarily succeeded. Future operations will attempt to open a new connection to the database (and will continue to raise this exception until the first successful connection is made).

Subclass of ConnectionFailure.

exception pymongo.errors.BulkWriteError(results)

Exception class for bulk write errors.

New in version 2.7.

exception pymongo.errors.CollectionInvalid

Raised when collection validation fails.

exception pymongo.errors.ConfigurationError

Raised when something is incorrectly configured.

exception pymongo.errors.ConnectionFailure

Raised when a connection to the database cannot be made or is lost.

exception pymongo.errors.CursorNotFound(error, code=None, details=None)

Raised while iterating query results if the cursor is invalidated on the server.

New in version 2.7.

exception pymongo.errors.DocumentTooLarge

Raised when an encoded document is too large for the connected server.

exception pymongo.errors.DuplicateKeyError(error, code=None, details=None)

Raised when an insert or update fails due to a duplicate key error.

exception pymongo.errors.ExceededMaxWaiters

Raised when a thread tries to get a connection from a pool and maxPoolSize * waitQueueMultiple threads are already waiting.

New in version 2.6.

exception pymongo.errors.ExecutionTimeout(error, code=None, details=None)

Raised when a database operation times out, exceeding the $maxTimeMS set in the query or command option.


Requires server version >= 2.6.0

New in version 2.7.

exception pymongo.errors.InvalidName

Raised when an invalid name is used.

exception pymongo.errors.InvalidOperation

Raised when a client attempts to perform an invalid operation.

exception pymongo.errors.InvalidURI

Raised when trying to parse an invalid mongodb URI.

exception pymongo.errors.NetworkTimeout(message='', errors=None)

An operation on an open connection exceeded socketTimeoutMS.

The remaining connections in the pool stay open. In the case of a write operation, you cannot know whether it succeeded or failed.

Subclass of AutoReconnect.

exception pymongo.errors.NotMasterError(message='', errors=None)

The server responded “not master” or “node is recovering”.

These errors result from a query, write, or command. The operation failed because the client thought it was using the primary but the primary has stepped down, or the client thought it was using a healthy secondary but the secondary is stale and trying to recover.

The client launches a refresh operation on a background thread, to update its view of the server as soon as possible after throwing this exception.

Subclass of AutoReconnect.

exception pymongo.errors.OperationFailure(error, code=None, details=None)

Raised when a database operation fails.

New in version 2.7: The details attribute.


The error code returned by the server, if any.


The complete error document returned by the server.

Depending on the error that occurred, the error document may include useful information beyond just the error message. When connected to a mongos the error document may contain one or more subdocuments if errors occurred on multiple shards.

exception pymongo.errors.ProtocolError

Raised for failures related to the wire protocol.

exception pymongo.errors.PyMongoError

Base class for all PyMongo exceptions.

exception pymongo.errors.ServerSelectionTimeoutError(message='', errors=None)

Thrown when no MongoDB server is available for an operation

If there is no suitable server for an operation PyMongo tries for serverSelectionTimeoutMS (default 30 seconds) to find one, then throws this exception. For example, it is thrown after attempting an operation when PyMongo cannot connect to any server, or if you attempt an insert into a replica set that has no primary and does not elect one within the timeout window, or if you attempt to query with a Read Preference that the replica set cannot satisfy.

exception pymongo.errors.WTimeoutError(error, code=None, details=None)

Raised when a database operation times out (i.e. wtimeout expires) before replication completes.

With newer versions of MongoDB the details attribute may include write concern fields like ‘n’, ‘updatedExisting’, or ‘writtenTo’.

New in version 2.7.

exception pymongo.errors.WriteConcernError(error, code=None, details=None)

Base exception type for errors raised due to write concern.

New in version 3.0.

exception pymongo.errors.WriteError(error, code=None, details=None)

Base exception type for errors raised during write operations.

New in version 3.0.