Question

I am trying to generate json date string for y’day. I am not sure how to generate it in RFC 3339 format.

from datetime import date, timedelta
yesterday = date.today() - timedelta(1)


def dthandler(obj):
        return obj.isoformat()

with io.open('out/test.json', 'w', encoding='utf-8') as outfile:
    json.dump(rdata, outfile, indent=4, sort_keys=True, default=dthandler)

which format the date as:

"Date": "2012-12-04", 

How can I write the formatter function to get RfC 3339 format.

I use python 3.x

Answer 1

yesterday is a datetime.date object. You could convert it to datetime.datetime object if you need time in the output:

from datetime import datetime, time, timedelta

yesterday = datetime.utcnow() - timedelta(days=1)
dt = datetime.combine(yesterday.date(), time(0, 0)) # midnight
rfc3339str = dt.isoformat() + "Z"

This should work both Python 2 and 3.