Serialization for non-standard types yields incorrect output

[ludokriss]

Hi,

I am using the event grid client SDK in python to generate custom events. I have come across an issue I can't seem to solve without going away from the event grid SDK.

The problem is that the event grid model serializer does not give me the correct output for when including types that are not the basic types. A simple reproducible example:

from azure.eventgrid.models import EventGridEvent
import datetime
import uuid

event=EventGridEvent(
            topic="test",
            id=uuid.uuid4(),
            subject="testUpdated",
            data={"time":datetime.datetime.now().replace(tzinfo=datetime.timezone.utc)},
            event_type="test.test",
            event_time=datetime.datetime.now().replace(tzinfo=datetime.timezone.utc),
            data_version=2.0,
)

print(event.serialize())

This would return

{'id': '3e02a22c-f327-4f62-af25-b71e0865888b', 'topic': 'product', 'subject': 'ProductUpdated', 'data': {'time': '2020-09-07 10:37:08.348679+00:00'}, 'eventType': 'supplychain.product', 'eventTime': '2020-09-07T10:37:08.348679Z', 'dataVersion': '2.0'}

the serialize is not called by me in the code I actually use, but it looks like that is what is called behind the scenes when I send off the event. I want the datetime (the key "time" in the above example) to be serialized just as the parent-level "event_time". My problem is not only with datetime as in the current example, but also with decimals.

I guess this fits in this repo and not in the EventGrid SDK repo, but feel free to redirect me there.

[ludokriss]

To follow up with a potential solution to the problem as well, you could implement a change in the current serialize_object to handle more types as it typically ends up here:

msrest-for-python/msrest/serialization.py

Lines 936 to 980 in 98e2ebe

	def serialize_object(self, attr, **kwargs):
	"""Serialize a generic object.
	This will be handled as a dictionary. If object passed in is not
	a basic type (str, int, float, dict, list) it will simply be
	cast to str.
	:param dict attr: Object to be serialized.
	:rtype: dict or str
	"""
	if attr is None:
	return None
	if isinstance(attr, ET.Element):
	return attr
	obj_type = type(attr)
	if obj_type in self.basic_types:
	return self.serialize_basic(attr, self.basic_types[obj_type], **kwargs)
	if obj_type is _long_type:
	return self.serialize_long(attr)
	if obj_type is unicode_str:
	return self.serialize_unicode(attr)
	# If it's a model or I know this dependency, serialize as a Model
	elif obj_type in self.dependencies.values() or isinstance(attr, Model):
	return self._serialize(attr)
	if obj_type == dict:
	serialized = {}
	for key, value in attr.items():
	try:
	serialized[self.serialize_unicode(key)] = self.serialize_object(
	value, **kwargs)
	except ValueError:
	serialized[self.serialize_unicode(key)] = None
	return serialized
	if obj_type == list:
	serialized = []
	for obj in attr:
	try:
	serialized.append(self.serialize_object(
	obj, **kwargs))
	except ValueError:
	pass
	return serialized
	return str(attr)

If you add some more types to this, so that you handle dates by passing datetime types to the date-serializer etc. then you are good.

[rakshith91]

Hi @ludokriss
Can you tell us what version of eventgrid sdk are you using? Also what version of python?

[lmazuel]

Hi @ludokriss
In case you're using an old one, we just released a complete revamping of the SDK as preview:
https://pypi.org/project/azure-eventgrid/2.0.0b1/

[ludokriss]

Hey, sorry that I didn't include versions. Here it is, with python 3.7:
azure-eventgrid==1.3.0
msrest==0.6.18

Tested the new SDK so versions:
azure-eventgrid==2.0.0b1
msrest==0.6.19

And the inconsistent behavior is still there. Btw., I like the new sdk 👍

[lmazuel]

Hi @ludokriss
Got it, may I ask you to provide a data that has all the type you could expect to work by default? You mentionned decimals, but instead of guessing an actual Python code dict would be awesome :).

Note: I'm happy you like this new SDK ;)

[lmazuel]

Could you try #224 ?

[ludokriss]

Hey, #224 works perfectly for datetime types, so 👍 on that one. Added a pull request on the #224 PR for decimal types if you want to include that as well