Python: Printing all hours between two datetime accounting for daylight saving

Question

I want to print all hours between given two datetime accounting for daylight savings.

This is what I have started at:

from datetime import date, timedelta as td, datetime

d1 = datetime(2008, 8, 15, 1, 1, 0)
d2 = datetime(2008, 9, 15, 1, 12, 4)

while(d1<d2):
    d1 = d1 + td(hours=1)
    print d1

But what do I do for daylight time savings. How do I jump or add an hour for daylight savings ?

Edit: Based on suggestion below I wrote the following code and it still prints the daylight savings time for 2016.

import pytz
from datetime import date, timedelta as td, datetime
eastern = pytz.timezone('US/Eastern')

d1 = eastern.localize(datetime(2016, 3, 11, 21, 0, 0))
d2 = eastern.localize(datetime(2016, 3, 12, 5, 0, 0))

d3 = eastern.localize(datetime(2016, 11, 4, 21, 0, 0))
d4 = eastern.localize(datetime(2016, 11, 5, 5, 0, 0))

while(d1<d2):
    print d1
    d1 = d1 + td(hours=1)

while(d3<d4):
    print d3
    d3 = d3 + td(hours=1)

Output:

2016-03-11 21:00:00-05:00
2016-03-11 22:00:00-05:00
2016-03-11 23:00:00-05:00
2016-03-12 00:00:00-05:00
2016-03-12 01:00:00-05:00
2016-03-12 02:00:00-05:00
2016-03-12 03:00:00-05:00
2016-03-12 04:00:00-05:00

2016-11-04 21:00:00-04:00
2016-11-04 22:00:00-04:00
2016-11-04 23:00:00-04:00
2016-11-05 00:00:00-04:00
2016-11-05 01:00:00-04:00
2016-11-05 02:00:00-04:00
2016-11-05 03:00:00-04:00
2016-11-05 04:00:00-04:00

Edit 2: Desired result: In march hour skips and at 2 AM it becomes 3 AM.

2016-03-11 23:00:00-05:00
2016-03-12 00:00:00-05:00
2016-03-12 01:00:00-05:00
2016-03-12 03:00:00-05:00

In Nov, an hour is added at 2 AM, so 2 AM repeats, it should look like:

2016-11-04 23:00:00-04:00
2016-11-05 00:00:00-04:00
2016-11-05 01:00:00-04:00
2016-11-05 02:00:00-04:00
2016-11-05 02:00:00-04:00
2016-11-05 03:00:00-04:00

Answer 1

according to pytz when you want to do datetime arithimetics using local times you need to use normalize() method to handle daylight saving times and other timezone transitions hence your you should modify you code to include this

import pytz
from datetime import date, timedelta as td, datetime
eastern = pytz.timezone('US/Eastern')

d1 = eastern.localize(datetime(2016, 3, 11, 21, 0, 0))
d2 = eastern.localize(datetime(2016, 3, 12, 5, 0, 0))

d3 = eastern.localize(datetime(2016, 11, 4, 21, 0, 0))
d4 = eastern.localize(datetime(2016, 11, 5, 5, 0, 0))

while(d1<d2):
    print d1
    d1 = eastern.normalize(d1 + td(hours=1))

while(d3<d4):
    print d3
    d3 = eastern.normalize(d3 + td(hours=1))

check pytz for more here