How to overcome “datetime.datetime not JSON serializable”?

Question

I have a basic dict as follows:

sample = {}
sample[\'title\'] = \"String\"
sample[\'somedate\'] = somedatetimehere
         


        

Answer 1

if you are using python3.7, then the best solution is using datetime.isoformat() and datetime.fromisoformat(); they work with both naive and aware datetime objects:

#!/usr/bin/env python3.7

from datetime import datetime
from datetime import timezone
from datetime import timedelta
import json

def default(obj):
    if isinstance(obj, datetime):
        return { '_isoformat': obj.isoformat() }
    return super().default(obj)

def object_hook(obj):
    _isoformat = obj.get('_isoformat')
    if _isoformat is not None:
        return datetime.fromisoformat(_isoformat)
    return obj

if __name__ == '__main__':
    #d = { 'now': datetime(2000, 1, 1) }
    d = { 'now': datetime(2000, 1, 1, tzinfo=timezone(timedelta(hours=-8))) }
    s = json.dumps(d, default=default)
    print(s)
    print(d == json.loads(s, object_hook=object_hook))

output:

{"now": {"_isoformat": "2000-01-01T00:00:00-08:00"}}
True

if you are using python3.6 or below, and you only care about the time value (not the timezone), then you can use datetime.timestamp() and datetime.fromtimestamp() instead;

if you are using python3.6 or below, and you do care about the timezone, then you can get it via datetime.tzinfo, but you have to serialize this field by yourself; the easiest way to do this is to add another field _tzinfo in the serialized object;

finally, beware of precisions in all these examples;