raw_bson – Tools for representing raw BSON documents.¶
Tools for representing raw BSON documents.
Inserting and Retrieving RawBSONDocuments¶
Example: Moving a document between different databases/collections
>>> import bson
>>> from pymongo import MongoClient
>>> from bson.raw_bson import RawBSONDocument
>>> client = MongoClient(document_class=RawBSONDocument)
>>> client.drop_database('db')
>>> client.drop_database('replica_db')
>>> db = client.db
>>> result = db.test.insert_many([{'_id': 1, 'a': 1},
... {'_id': 2, 'b': 1},
... {'_id': 3, 'c': 1},
... {'_id': 4, 'd': 1}])
>>> replica_db = client.replica_db
>>> for doc in db.test.find():
... print(f"raw document: {doc.raw}")
... print(f"decoded document: {bson.decode(doc.raw)}")
... result = replica_db.test.insert_one(doc)
raw document: b'...'
decoded document: {'_id': 1, 'a': 1}
raw document: b'...'
decoded document: {'_id': 2, 'b': 1}
raw document: b'...'
decoded document: {'_id': 3, 'c': 1}
raw document: b'...'
decoded document: {'_id': 4, 'd': 1}
For use cases like moving documents across different databases or writing binary blobs to disk, using raw BSON documents provides better speed and avoids the overhead of decoding or encoding BSON.
- bson.raw_bson.DEFAULT_RAW_BSON_OPTIONS: bson.codec_options.CodecOptions = CodecOptions(document_class=<class 'bson.raw_bson.RawBSONDocument'>, tz_aware=False, uuid_representation=UuidRepresentation.UNSPECIFIED, unicode_decode_error_handler='strict', tzinfo=None, type_registry=TypeRegistry(type_codecs=[], fallback_encoder=None))¶
The default
CodecOptionsforRawBSONDocument.
- class bson.raw_bson.RawBSONDocument(bson_bytes: bytes, codec_options: Optional[bson.codec_options.CodecOptions] = None)¶
Create a new
RawBSONDocumentRawBSONDocumentis a representation of a BSON document that provides access to the underlying raw BSON bytes. Only when a field is accessed or modified within the document does RawBSONDocument decode its bytes.RawBSONDocumentimplements theMappingabstract base class from the standard library so it can be used like a read-onlydict:>>> from bson import encode >>> raw_doc = RawBSONDocument(encode({'_id': 'my_doc'})) >>> raw_doc.raw b'...' >>> raw_doc['_id'] 'my_doc'
- Parameters
bson_bytes: the BSON bytes that compose this document
codec_options (optional): An instance of
CodecOptionswhosedocument_classmust beRawBSONDocument. The default isDEFAULT_RAW_BSON_OPTIONS.
Changed in version 3.8:
RawBSONDocumentnow validates that thebson_bytespassed in represent a single bson document.Changed in version 3.5: If a
CodecOptionsis passed in, its document_class must beRawBSONDocument.