如何在python中添加两个偏移量？

Question

I am getting a offset form the pytz library from the following line:

 offset = datetime.datetime.now(pytz.timezone(timezone)).strftime('%z')

First i pass the US/Eastern in timezone variable and then i pass the Asia/Kolkata in timezone variable which prints the following value

 local_utc = -0400
 user_utc = +0530

After getting these values i converted it from string to int by following code:

local_utc = int(local_utc)
user_urc = int(user_utc)

Apart from this i have a timetuple also:

 hour, minute,days = (timezone_tuple.tm_hour, timezone_tuple.tm_min,
                        timezone_tuple.tm_mday)

I want to add the difference of local_utc and user_utc to above tuple such as -0400: 04 such as hour and 00 as minutes. For example: difference will be : 0930 . And 09 will be add to timezone_tuple.tm_hour and 30 will be add to timezone_tuple.tm_min

I didn't found any situation. how can it be possible? Is there any way to do with spilit method

Answer 1

Your post showed how to find local_utc and user_utc as integers. You could just take the difference local_utc-user_utc to determine the relative offset.

However, datetime , time and pytz should give you all the tools you need to manipulate times without having to parse offsets and do such calculations "manually".

For example,

import pytz
import datetime as dt
import time

eastern = pytz.timezone('US/Eastern')
kolkata = pytz.timezone('Asia/Kolkata')

naive_timetuple = time.localtime(0)
print(naive_timetuple)
# time.struct_time(tm_year=1969, tm_mon=12, tm_mday=31, tm_hour=19, tm_min=0, tm_sec=0, tm_wday=2, tm_yday=365, tm_isdst=0)

Above, I defined a naive timetuple. Below, I "localize" it to US/Eastern time -- that is, make it a timezone-aware datetime:

naive_datetime = dt.datetime(*naive_timetuple[:6])
print(naive_datetime)
# 1969-12-31 19:00:00

localized_datetime = eastern.localize(naive_datetime)
print(localized_datetime)
# 1969-12-31 19:00:00-05:00

Now to convert a timezone-aware datetime to any other timezone, use the astimezone method:

kolkata_datetime = localized_datetime.astimezone(kolkata)
print(kolkata_datetime)
# 1970-01-01 05:30:00+05:30

And if you need to convert a datetime back to a timetuple, use the timetuple method:

kolkata_timetuple = kolkata_datetime.timetuple()
print(kolkata_timetuple)
# time.struct_time(tm_year=1970, tm_mon=1, tm_mday=1, tm_hour=5, tm_min=30, tm_sec=0, tm_wday=3, tm_yday=1, tm_isdst=0)