I am trying to compare the current date and time with dates and times specified in models using comparison operators:
if challenge.datetime_start <= datetime.now() <= challenge.datetime_end:
The script errors out with:
TypeError: can't compare offset-naive and offset-aware datetimes
The models look like this:
class Fundraising_Challenge(models.Model): name = models.CharField(max_length=100) datetime_start = models.DateTimeField() datetime_end = models.DateTimeField()
I also have django using locale date and times.
What I haven't been able to find is the format django uses for DateTimeField(). Is it naive or aware? And how do I get datetime.now() to recognize locale datetime?
By default, the
datetime object is
naive in Python, so you need to make both of them either naive or aware
datetime objects. This can be done using:
import datetime import pytz utc=pytz.UTC challenge.datetime_start = utc.localize(challenge.datetime_start) challenge.datetime_end = utc.localize(challenge.datetime_end) # now both the datetime objects are aware, and you can compare them
Note: This would raise a
tzinfo is already set. If you are not sure about that, just use
start_time = challenge.datetime_start.replace(tzinfo=utc) end_time = challenge.datetime_end.replace(tzinfo=utc)
BTW, you could format a UNIX timestamp in datetime.datetime object with timezone info as following
d = datetime.datetime.utcfromtimestamp(int(unix_timestamp)) d_with_tz = datetime.datetime( year=d.year, month=d.month, day=d.day, hour=d.hour, minute=d.minute, second=d.second, tzinfo=pytz.UTC)
datetime.datetime.now is not timezone aware.
Django comes with a helper for this, which requires
from django.utils import timezone now = timezone.now()
You should be able to compare