pygsti.baseobjs.mongoserializable.MongoSerializable

pygsti.baseobjs.mongoserializable.MongoSerializable#

class MongoSerializable(doc_id=None)#

Bases: object

Base class for objects that can be serialized to a MongoDB database.

At the very least, saving an object to a database creates a document in the collection named by the collection_name class variable (which can be overridden by derived classes). Additionally, saving the object may create other documents outside of this collection (e.g., if the object contains MongoSerializable attributes that specify their own collection name).

This interface also allows an object to save large chunks of data using, e.g., MongoDB’s GridFS system, when serializing itself instead of trying to write an enormous JSON dictionary as a single document (as an object that is NicelySerializable might do).

Methods

__init__([doc_id])

add_mongodb_write_ops(write_ops, mongodb[, ...])

Accumulate write and update operations for writing this object to a MongoDB database.

from_mongodb(mongodb, doc_id, **kwargs)

Create and initialize an object from a MongoDB instance.

from_mongodb_doc(mongodb, collection_name, ...)

Create and initialize an object from a MongoDB instance and pre-loaded primary document.

remove_from_mongodb(mongodb, doc_id[, ...])

Remove the documents corresponding to an instance of this class from a MongoDB database.

remove_me_from_mongodb(mongodb[, session, ...])

write_to_mongodb(mongodb[, session, ...])

Write this object to a MongoDB database.

Attributes

collection_name

add_mongodb_write_ops(write_ops, mongodb, overwrite_existing=False, **kwargs)#

Accumulate write and update operations for writing this object to a MongoDB database.

Similar to write_to_mongodb() but collects write operations instead of actually executing any write operations on the database. This function may be preferred to write_to_mongodb() when this object is being written as a part of a larger entity and executing write operations is saved until the end.

As in write_to_mongodb(), self.collection_name is the collection name and _id is either: 1) the ID used by a previous write or initial read-in, if one exists, OR 2) a new random bson.objectid.ObjectId

Parameters:

  • write_ops (WriteOpsByCollection) – An object that keeps track of pymongo write operations on a per-collection basis. This object accumulates write operations to be performed at some point in the future.

  • mongodb (pymongo.database.Database) – The MongoDB instance to write data to.

  • overwrite_existing (bool, optional) – Whether existing documents should be overwritten. The default of False causes a ValueError to be raised if a document with the given _id already exists and is different from what is being written.

  • **kwargs (dict) – Additional keyword arguments potentially used by subclass implementations. Any arguments allowed by a subclass’s _add_auxiliary_write_ops_and_update_doc method is allowed here.

Returns:

The identifier (_id value) of the main document that was written.

Return type:

bson.objectid.ObjectId

classmethod from_mongodb(mongodb, doc_id, **kwargs)#

Create and initialize an object from a MongoDB instance.

Parameters:

  • mongodb (pymongo.database.Database) – The MongoDB instance to load from.

  • doc_id (bson.objecctid.ObjectId or dict) – The object ID or filter used to find a single object ID within the database. This document is loaded from the collection given by the collection_name attribute of this class.

  • **kwargs (dict) – Additional keyword arguments potentially used by subclass implementations. Any arguments allowed by a subclass’s _create_obj_from_doc_and_mongodb method is allowed here.

Return type:

object

classmethod from_mongodb_doc(mongodb, collection_name, doc, **kwargs)#

Create and initialize an object from a MongoDB instance and pre-loaded primary document.

Parameters:

  • mongodb (pymongo.database.Database) – The MongoDB instance to load from.

  • collection_name (str) – The collection name within mongodb that doc was loaded from. This is needed for the sole purpose of setting the created (returned) object’s database “coordinates”.

  • doc (dict) – The already-retrieved main document for the object being loaded. This takes the place of giving an identifier for this object.

  • **kwargs (dict) – Additional keyword arguments potentially used by subclass implementations. Any arguments allowed by a subclass’s _create_obj_from_doc_and_mongodb method is allowed here.

Return type:

object

classmethod remove_from_mongodb(mongodb, doc_id, collection_name=None, session=None, recursive='default')#

Remove the documents corresponding to an instance of this class from a MongoDB database.

Parameters:

  • mongodb (pymongo.database.Database) – The MongoDB instance to remove documents from.

  • doc_id (bson.objectid.ObjectId) – The identifier of the root document stored in the database.

  • collection_name (str, optional) – the MongoDB collection within mongodb where the main document resides. If None, then <this_class>.collection_name is used (which is usually what you want).

  • session (pymongo.client_session.ClientSession, optional) – MongoDB session object to use when interacting with the MongoDB database. This can be used to implement transactions among other things.

  • recursive (RecursiveRemovalSpecification, optional) – An object that filters the type of documents that are removed. Used when working with inter-related experiment designs, data, and results objects to only remove the types of documents you know aren’t being shared with other documents.

Return type:

None

write_to_mongodb(mongodb, session=None, overwrite_existing=False, **kwargs)#

Write this object to a MongoDB database.

The collection name used is self.collection_name, and the _id is either: 1) the ID used by a previous write or initial read-in, if one exists, OR 2) a new random bson.objectid.ObjectId

Parameters:

  • mongodb (pymongo.database.Database) – The MongoDB instance to write data to.

  • session (pymongo.client_session.ClientSession, optional) – MongoDB session object to use when interacting with the MongoDB database. This can be used to implement transactions among other things.

  • overwrite_existing (bool, optional) – Whether existing documents should be overwritten. The default of False causes a ValueError to be raised if a document with the given _id already exists and is different from what is being written.

  • **kwargs (dict) – Additional keyword arguments potentially used by subclass implementations. Any arguments allowed by a subclass’s _add_auxiliary_write_ops_and_update_doc method is allowed here.

Returns:

The identifier (_id value) of the main document that was written.

Return type:

bson.objectid.ObjectId