Python - printing UTC dates in ISO8601 format with time zone

By default, when you make a UTC date from a Unix timestamp in Python and print it in ISO format, it has no time zone:

$ python3
>>> from datetime import datetime
>>> datetime.utcfromtimestamp(1496998804).isoformat()
'2017-06-09T09:00:04'

Whenever you talk about a datetime, I think you should always include a time zone, so I find this problematic.

The solution is to mention the timezone explicitly when you create the datetime:

$ python3
>>> from datetime import datetime, timezone
>>> datetime.fromtimestamp(1496998804, tz=timezone.utc).isoformat()
'2017-06-09T09:00:04+00:00'

Note, including the timezone explicitly works the same way when creating a datetime in other ways:

$ python3
>>> from datetime import datetime, timezone
>>> datetime(2017, 6, 9).isoformat()
'2017-06-09T00:00:00'
>>> datetime(2017, 6, 9, tzinfo=timezone.utc).isoformat()
'2017-06-09T00:00:00+00:00'