Codec options

[gp-cp]

Hi,

how to add codec_options to support custom types in mongo?
Example:
`
from bson.codec_options import TypeCodec, CodecOptions, TypeRegistry

class SetCodec(TypeCodec):

python_type = set
bson_type = list

def transform_python(self, value):
    return list(value)

def transform_bson(self, value):
    return value

set_codec = SetCodec()
type_registry = TypeRegistry([set_codec])
codec_options = CodecOptions(type_registry=type_registry)
client.get_database(name="foobar", codec_options=codec_options)
`

[IGJAmpere]

Hi!
I am also interested in pymongo's CodecOptions for datetime readings, as my code was breaking because it was not able to compare naive to non-naive datetimes.

I have been able to apply this at the database level changing the system of retrieving/generating the database, like this:

    from motor import AsyncIOMotorClient
    from bson.codec_options import CodecOptions
    from datetime import timezone

    CODEC_OPTIONS = CodecOptions(tz_aware=True, tzinfo=timezone.utc)
    client = AsyncIOMotorClient("mongodb://localhost:27017")
    db = client.get_database("test_db", codec_options=CODEC_OPTIONS)
    await init_beanie(database=db, document_models=...)

But it would be nice to have this CodecOptions accessible maybe on a per collection level (as shown in pymongo's docs above), possibly through Document's Settings inner class.

Maybe the option is already there, hopefully something like this will be documented.

[roman-right]

This sounds reasonable. I'll add this feature to my ToDo list.

[Mark90]

Nice, I wasn't aware of the CodecOptions fix!

Since the BSON date type is considered UTC, would it perhaps make sense for beanie to always return datetime objects with tzinfo set to utc?

[IGJAmpere]

In Python, naive datetime objects are basically the default (sadly, in my opinion), so I think enforcing UTC timezones might cause more unexpected problems to some users, as you cannot operate naive with aware (it crashes).

So, I'd say the best solution is for this to be easily toggleable, and well documented in Beanie.

---

As a side note, these Python guys thought that datetime.utcnow had to return a naive datetime... so... yeah...

[Mark90]

So, I'd say the best solution is for this to be easily toggleable, and well documented in Beanie.

Fully agree, it could be part of an option like strict_datetimes which, when enabled, would make documents return (and require) aware datetimes. But I don't know how much extra work this puts on Roman's plate :)

As a side note, these Python guys thought that datetime.utcnow had to return a naive datetime... so... yeah...

Yep, I think this contributes to keeping developers in the dark about timezones.