Python: What date/time is it in NYC? (without pytz)

In Python, I want a Python program to be able to determine the current date and time in NYC . Is that practical? While datetime.datetime.now() can tell me the local time, and datetime.utcnow() can tell me the UTC (GMT). However just looking at the difference will not help me as DST changes.

I try things like "dt=datetime.now() " and "dt.timetuple()" I get tm_isdst=-1 even if I change the computer date.

I change my computer clock from a January date to a July date. I still get tm_isdst=-1

Why not use pytz?开发者_如何学JAVA I want the users to not have to go thru the step of downloading an extra library.

---

I suspect some sort of problems in your use of the datetime, time, etc. modules, but without knowing more, not much help can be provided.

The following suggestion has some definite drawbacks, and I really recommend more pursuit to solving the problems with datetime, etc. However, if you're sure to have a web connection and need to get something done fast, you could query USNO time with something like:

import urllib
f = urllib.urlopen("http://tycho.usno.navy.mil/cgi-bin/timer.pl")
time_page = f.readlines()
for line in time_page:
    if line.find("Eastern Time") != -1:
        ny_time = line[4:24]
        break
print ny_time

The output looks like:

Jan. 19, 05:18:04 PM

This makes use of the fact that NYC is in the Eastern Time zone. Also, it assumes the USNO server is available to your user. Furthermore, it has assumptions about the format of the content returned. I don't know if/how frequently that format changes. Also, if this is going to be used a lot, please find another server, as you don't want to sink the USNO server! (Pun not originally intended, but recognized and kept. :-).

---

If you are not in the same timezone as NYC, it's in practice impossible without knowing the timezone and when DST changes. You can't hardcode it for NYC, of course, but it is way easier to just install pytz or dateutil, and then you aren't limited to NYC.