Python and RFC 3339 timestamps

Question

Where can I find a routine for building an RFC 3339 time?

Answer 1

This was based on the examples on page 10 of the RFC. The only difference is that I am showing a microseconds value of six digits, conformant to Google Drive's timestamps.

from math import floor

def build_rfc3339_phrase(datetime_obj):
    datetime_phrase = datetime_obj.strftime('%Y-%m-%dT%H:%M:%S')
    us = datetime_obj.strftime('%f')

    seconds = datetime_obj.utcoffset().total_seconds()

    if seconds is None:
        datetime_phrase += 'Z'
    else:
        # Append: decimal, 6-digit uS, -/+, hours, minutes
        datetime_phrase += ('.%.6s%s%02d:%02d' % (
                            us,
                            ('-' if seconds < 0 else '+'),
                            abs(int(floor(seconds / 3600))),
                            abs(seconds % 3600)
                            ))

    return datetime_phrase

Answer 2

python-rfc3339 worked great for me.

Answer 3

rfc3339 is very flexible - http://www.ietf.org/rfc/rfc3339.txt - it effectively defines a whole pile of formats. you can generate almost all of them just using the standard python time formatting - http://docs.python.org/3.3/library/datetime.html#strftime-strptime-behavior

however, there is one oddity, and that is they allow (it's optional) a : between hours and minutes in a numerical timezone offset (%z). python won't display that, so if you want to include that you need python-rfc3339 or similar.

for parsing rfc3339, simple-date will handle all formats. but since it uses python print routines it cannot handle the : case above.