string to datetime with fractional seconds, on Google App Engine

Question

I need to convert a string to a datetime object, along with the fractional seconds. I\'m running into various problems.

Normally, i would do:

>>>         


        

Answer 1

Parsing

Without the %f format support for datetime.datetime.strptime() you can still sufficiently easy enter it into a datetime.datetime object (randomly picking a value for your val here) using datetime.datetime.replace()), tested on 2.5.5:

>>> val = '2010-08-06T10:00:14.143896'
>>> nofrag, frag = val.split('.')
>>> nofrag_dt = datetime.datetime.strptime(nofrag, "%Y-%m-%dT%H:%M:%S")
>>> dt = nofrag_dt.replace(microsecond=int(frag))
>>> dt
datetime.datetime(2010, 8, 6, 10, 0, 14, 143896)

Now you have your datetime.datetime object.

Storing

Reading further into http://code.google.com/appengine/docs/python/datastore/typesandpropertyclasses.html#datetime

I can see no mentioning that fractions isn't supported, so yes, it's probably only the datastore viewer. The docs points directly to Python 2.5.2's module docs for datetime, and it does support fractions, just not the %f parsing directive for strptime. Querying for fractions might be trickier, though..

Answer 2

All ancient history by now, but in these modern times you can also conveniently use dateutil

from dateutil import parser as DUp

funky_time_str = "1/1/2011 12:51:00.0123 AM"

foo = DUp.parse(funky_time_str)

print foo.timetuple()
# time.struct_time(tm_year=2011, tm_mon=1, tm_mday=1, tm_hour=0, tm_min=51, tm_sec=0, tm_wday=5, tm_yday=1, tm_isdst=-1)

print foo.microsecond
# 12300

print foo
# 2011-01-01 00:51:00.012300

dateutil supports a surprising variety of possible input formats, which it parses without pattern strings.