在Python中比较两个日期的不同格式

Question

I'm not familiar with Python, just debugging an existing code. I'm comparing two dates here but they have different formats. I get the "TypeError: can't compare offset-naive and offset-aware datetimes" when I do the compare.

if date_start <= current_date:

"TypeError: can't compare offset-naive and offset-aware

str(date_start) >> 2015-08-24 16:25:00+00:00

str(current_date) >> 2015-08-24 17:58:42.092391

How do I make a valid date comparison? I'm assuming I need to convert one to another format.

UPDATE

hour_offset = 0
minute_offset = 0
if timezone_offset:
    offset_sign = int('%s1' % timezone_offset[0])
    hour_offset = offset_sign * int(timezone_offset[1:3])
    minute_offset = offset_sign * int(timezone_offset[3:5])    
    current_date = (datetime.datetime.now() + 
        datetime.timedelta(hours=hour_offset,minutes=minute_offset))

The previous dev might have applied the timezone offset this way. Any thoughts on this one?

Answer 1

使用dt.replace(tzinfo=tz)将时区添加到原始日期时间，以便可以进行比较。

Answer 2

There is no more details here to solve.But if you want to get a offset-naive time.Try this

(offset-aware-datetime).replace(tzinfo=None)

To add a timezone to offset-naive time.Try this

(offset-naive-datetime).replace(tzinfo=tz)

Answer 3

One way is to convert the date to seconds since epoch and then compare. Say,if your date is 2015-08-24 16:25:00 then you can convert to seconds using datetime method. It takes parameters as (year, month, day[, hour[, minute[,second[, microsecond[, tzinfo]]]]]) . It returns a datetime object. Finally, you can use strftime() to get seconds as a zero-padded decimal number. So your code can be:

import datetime
d1 = datetime.datetime(2015,8,24,16,25,0)
d2 = datetime.datetime(2015,8,24,17,58,42,92391)
if int(d1.strftime("%s")) > int(d2.strftime("%s")):
    print "First one is bigger"
else:
    print "Second one is bigger"

I hope this helps!