codec_options
– Tools for specifying BSON codec options¶
Tools for specifying BSON codec options.
- class bson.codec_options.CodecOptions(document_class=None, tz_aware=False, uuid_representation=0, unicode_decode_error_handler='strict', tzinfo=None, type_registry=None, datetime_conversion=DatetimeConversion.DATETIME)¶
Encapsulates options used encoding and / or decoding BSON.
The document_class option is used to define a custom type for use decoding BSON documents. Access to the underlying raw BSON bytes for a document is available using the
RawBSONDocument
type:>>> from bson.raw_bson import RawBSONDocument >>> from bson.codec_options import CodecOptions >>> codec_options = CodecOptions(document_class=RawBSONDocument) >>> coll = db.get_collection('test', codec_options=codec_options) >>> doc = coll.find_one() >>> doc.raw '\x16\x00\x00\x00\x07_id\x00[0\x165\x91\x10\xea\x14\xe8\xc5\x8b\x93\x00'
The document class can be any type that inherits from
MutableMapping
:>>> class AttributeDict(dict): ... # A dict that supports attribute access. ... def __getattr__(self, key): ... return self[key] ... def __setattr__(self, key, value): ... self[key] = value ... >>> codec_options = CodecOptions(document_class=AttributeDict) >>> coll = db.get_collection('test', codec_options=codec_options) >>> doc = coll.find_one() >>> doc._id ObjectId('5b3016359110ea14e8c58b93')
See Datetimes and Timezones for examples using the tz_aware and tzinfo options.
See Handling UUID Data for examples using the uuid_representation option.
- Parameters:
document_class (Type[Mapping[str, Any]]) – BSON documents returned in queries will be decoded to an instance of this class. Must be a subclass of
MutableMapping
. Defaults todict
.tz_aware (bool) – If
True
, BSON datetimes will be decoded to timezone aware instances ofdatetime
. Otherwise they will be naive. Defaults toFalse
.uuid_representation (int) – The BSON representation to use when encoding and decoding instances of
UUID
. Defaults toUNSPECIFIED
. New applications should consider setting this toSTANDARD
for cross language compatibility. See Handling UUID Data for details.unicode_decode_error_handler (str) – The error handler to apply when a Unicode-related error occurs during BSON decoding that would otherwise raise
UnicodeDecodeError
. Valid options include ‘strict’, ‘replace’, ‘backslashreplace’, ‘surrogateescape’, and ‘ignore’. Defaults to ‘strict’.tzinfo (tzinfo | None) – A
tzinfo
subclass that specifies the timezone to/from whichdatetime
objects should be encoded/decoded.type_registry (TypeRegistry) – Instance of
TypeRegistry
used to customize encoding and decoding behavior.datetime_conversion (DatetimeConversion | None) – Specifies how UTC datetimes should be decoded within BSON. Valid options include ‘datetime_ms’ to return as a DatetimeMS, ‘datetime’ to return as a datetime.datetime and raising a ValueError for out-of-range values, ‘datetime_auto’ to return DatetimeMS objects when the underlying datetime is out-of-range and ‘datetime_clamp’ to clamp to the minimum and maximum possible datetimes. Defaults to ‘datetime’.
- Return type:
Changed in version 4.0: The default for uuid_representation was changed from
PYTHON_LEGACY
toUNSPECIFIED
.Added in version 3.8: type_registry attribute.
Warning
Care must be taken when changing unicode_decode_error_handler from its default value (‘strict’). The ‘replace’ and ‘ignore’ modes should not be used when documents retrieved from the server will be modified in the client application and stored back to the server.
- with_options(**kwargs)¶
Make a copy of this CodecOptions, overriding some options:
>>> from bson.codec_options import DEFAULT_CODEC_OPTIONS >>> DEFAULT_CODEC_OPTIONS.tz_aware False >>> options = DEFAULT_CODEC_OPTIONS.with_options(tz_aware=True) >>> options.tz_aware True
Added in version 3.5.
- Parameters:
kwargs (Any)
- Return type:
- class bson.codec_options.DatetimeConversion(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)¶
Options for decoding BSON datetimes.
- DATETIME = 1¶
Decode a BSON UTC datetime as a
datetime.datetime
.BSON UTC datetimes that cannot be represented as a
datetime
will raise anOverflowError
or aValueError
.
- DATETIME_AUTO = 4¶
Decode a BSON UTC datetime as a
datetime.datetime
if possible, and aDatetimeMS
if not.
- DATETIME_CLAMP = 2¶
Decode a BSON UTC datetime as a
datetime.datetime
, clamping tomin
andmax
.
- DATETIME_MS = 3¶
Decode a BSON UTC datetime as a
DatetimeMS
object.
- class bson.codec_options.TypeCodec¶
Base class for defining type codec classes which describe how a custom type can be transformed to/from one of the types
bson
can already encode/decode.Codec classes must implement the
python_type
attribute, and thetransform_python
method to support encoding, as well as thebson_type
attribute, and thetransform_bson
method to support decoding.See The TypeCodec Class documentation for an example.
- class bson.codec_options.TypeDecoder¶
Base class for defining type codec classes which describe how a BSON type can be transformed to a custom type.
Codec classes must implement the
bson_type
attribute, and thetransform_bson
method to support decoding.See The TypeCodec Class documentation for an example.
- class bson.codec_options.TypeEncoder¶
Base class for defining type codec classes which describe how a custom type can be transformed to one of the types BSON understands.
Codec classes must implement the
python_type
attribute, and thetransform_python
method to support encoding.See The TypeCodec Class documentation for an example.
- class bson.codec_options.TypeRegistry(type_codecs=None, fallback_encoder=None)¶
Encapsulates type codecs used in encoding and / or decoding BSON, as well as the fallback encoder. Type registries cannot be modified after instantiation.
TypeRegistry
can be initialized with an iterable of type codecs, and a callable for the fallback encoder:>>> from bson.codec_options import TypeRegistry >>> type_registry = TypeRegistry([Codec1, Codec2, Codec3, ...], ... fallback_encoder)
See The TypeRegistry Class documentation for an example.
- Parameters:
type_codecs (Optional[Iterable[_Codec]]) – iterable of type codec instances. If
type_codecs
contains multiple codecs that transform a single python or BSON type, the transformation specified by the type codec occurring last prevails. A TypeError will be raised if one or more type codecs modify the encoding behavior of a built-inbson
type.fallback_encoder (Optional[_Fallback]) – callable that accepts a single, unencodable python value and transforms it into a type that
bson
can encode. See The fallback_encoder Callable documentation for an example.