DeserializationError: Invalid type: "datetime.datetime" when deserializing correct datetime string into Optional[datetime]

[aadamvanko]

DeserializationError: Invalid type: "datetime.datetime" when deserializing correct datetime string into Optional[datetime]

[ramonhagenaars]

Hi aadamvanko.

In your code, you tried to use jsons.load on a dict that was already (largely) deserialized on this line: withDateDict = jsons.loads(withDateStr). The jsons.load function only allows dicts with types that have a JSON equivalent (i.e. str, int, float, bool, list, tuple, set, dict and NoneType, not datetime.datetime).

If you want to deserialize a string, you could just use jsons.loads.

withDateStr = '''{"created":"2019-12-19T11:40:48Z"}'''
# withDateDict = jsons.loads(withDateStr)  <-- No need for this
# print(withDateDict)
withDateObj = jsons.loads(withDateStr, WithDateOK)  # <-- loads instead of load
withDateObj = jsons.loads(withDateStr, WithDateBad)  # <-- loads instead of load
print(type(withDateObj))
print(withDateObj)

Or, if you actually intended to do it in two steps, you should use json.loads instead:

withDateStr = '''{"created":"2019-12-19T11:40:48Z"}'''
withDateDict = json.loads(withDateStr)  # <-- json instead of jsons
print(withDateDict)
withDateObj = jsons.load(withDateDict, WithDateOK)
withDateObj = jsons.load(withDateDict, WithDateBad)
print(type(withDateObj))
print(withDateObj)

Hope that helps!

Regards,
Ramon

[aadamvanko]

Thanks for the clarification, it is kind of misleading with json and also jsons and both have load and loads and works little bit differently from what you have shown, but my code works like it should so thank you.

Regards,
Adam