In Python 2, objects automatically inherit the __hash__ of their parent
class. In Python 3, objects that override __eq__ do not automatically inherit
__hash__, so these objects were not hashable under Python 3. Additionally,
mutable BSON types and types that overide __eq__ but did not explicitly define
__hash__ had broken __hash__ methods under Python 2. This commit unifies the
hashing behavior between Python versions and fixes the __hash__ methods such
that two BSON objects hash the same only if they are equal.
N.B.: bson.code.Code and bson.regex.Regex are no longer hashable under Python 2
because they are mutable.
This change resolves four issues:
PYTHON-826 The new codec_options submodule is moved from pymongo to bson.
PYTHON-827 Use codec_options in BSON APIs.
Functions and methods of the bson module that accepted the options as_class,
tz_aware, and uuid_subtype now accept a codec_options parameter instead.
For example, the function definition for bson.decode_all changes from this:
def decode_all(data, as_class=dict, tz_aware=True,
uuid_subtype=OLD_UUID_SUBTYPE)
to:
def decode_all(data, codec_options=CodecOptions())
The following functions are changed:
- decode_all
- decode_iter
- decode_file_iter
The following methods are changed:
- BSON.encode
- BSON.decode
This is a breaking change for any application that uses the BSON API directly
and changes any of the named parameter defaults. No changes are required for
applications that use the default values for these options. The behavior
remains the same.
PYTHON-828 Internal BSON module changes to support CodecOptions
The pure Python BSON module passes around a CodecOptions instance instead of
as_class, tz_aware, and uuid_subtype. C extensions pass these values around in
a struct.
PYTHON-801 Rename uuid_subtype to uuid_representation.
When decoding large collections of bson documents, the python representation
of dicts are time and space costly, so it's sometimes useful to generate and
consume the documents iteratively. This patch adds two new functions to do
that: decode_iter and decode_file_iter. The first is given all the bson data,
but yields one document at a time, while the second reads from a file object
enough to yield one document at a time (to avoid reading in an entire file).
Add a 'compile_re' parameter to Collection.find, Collection.find_one, and
json_util.loads. If it's False, regular expressions are encoded as a new class,
Regex, instead of passed to re.compile(). This allows PyMongo to handle regular
expressions that don't compile in Python but are valid in other contexts like
MongoDB queries.
The default binary subtype for UUIDs has changed
to 4. You can use bson.binary.UUIDLegacy to query
on UUIDs previously stored as subtype 3. See the
UUIDLegacy docstring for more details.
