Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #96526

Re: [Datetime-SIG] Are there any "correct" implementations of tzinfo?

Path csiph.com!news.mixmin.net!newsreader4.netcologne.de!news.netcologne.de!bcyclone01.am1.xlned.com!bcyclone01.am1.xlned.com!newsfeed.xs4all.nl!newsfeed7.news.xs4all.nl!nzpost1.xs4all.net!not-for-mail
Return-Path <lac@openend.se>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.000
X-Spam-Evidence '*H*': 1.00; '*S*': 0.00; 'subject:: [': 0.03; 'operator': 0.03; 'api.': 0.04; 'think,': 0.05; '(so': 0.07; 'conversions': 0.07; 'cc:addr:python-list': 0.09; 'creighton': 0.09; 'dst,': 0.09; 'happen.': 0.09; 'received:openend.se': 0.09; 'received:theraft.openend.se': 0.09; 'sane': 0.09; 'span': 0.09; 'tickets.': 0.09; 'wrong,': 0.09; 'python': 0.10; 'packages.': 0.15; 'alexander': 0.16; 'already,': 0.16; 'cc:addr:lac': 0.16; 'cc:addr:openend.se': 0.16; 'cc:name:laura creighton': 0.16; 'from:addr:lac': 0.16; 'from:addr:openend.se': 0.16; 'from:name:laura creighton': 0.16; 'message-id:@fido.openend.se': 0.16; 'peters': 0.16; 'railroad': 0.16; 'received:fido': 0.16; 'received:fido.openend.se': 0.16; 'relatives': 0.16; 'scrape': 0.16; 'uses,': 0.16; 'utc': 0.16; 'utc.': 0.16; 'app': 0.16; 'laura': 0.18; '(in': 0.18; 'subject:] ': 0.19; '2015': 0.20; 'cc:addr:python.org': 0.20; 'cc:2**2': 0.20; 'issue.': 0.20; 'saying': 0.22; 'clock': 0.22; 'sep': 0.22; 'subject:skip:i 10': 0.22; 'cc:no real name:2**0': 0.22; 'thus': 0.24; 'tim': 0.24; 'written': 0.24; 'sort': 0.25; 'correct': 0.28; 'this.': 0.28; 'fine': 0.28; '-0500,': 0.29; 'comparison': 0.29; 'pep': 0.29; 'received:se': 0.29; 'convert': 0.29; 'themselves': 0.29; 'getting': 0.33; 'case,': 0.34; 'schedule': 0.34; 'add': 0.34; 'gives': 0.35; 'skip:> 10': 0.35; 'asking': 0.35; 'problem.': 0.35; 'but': 0.36; 'basic': 0.36; 'heard': 0.36; 'subject:" ': 0.36; 'subject:?': 0.36; 'expect': 0.37; 'thought': 0.37; 'charset :us-ascii': 0.37; 'means': 0.39; 'why': 0.39; 'does': 0.39; 'subject:-': 0.39; 'some': 0.40; 'him': 0.60; 'your': 0.60; 'avoid': 0.61; 'header:Message-Id:1': 0.61; 'telling': 0.61; 'back': 0.62; 'here.': 0.62; 'skip:n 10': 0.62; 'distance': 0.63; 'different': 0.63; 'here:': 0.63; 'times': 0.63; 'brain': 0.66; 'past.': 0.66; 'subject:there': 0.66; '495': 0.84; '>if': 0.84; '>of': 0.84; 'header:In-reply-to:1': 0.84; 'subject:any': 0.84; 'via,': 0.84; 'dozen': 0.91; 'time)': 0.91; 'subject:Are': 0.95; 'hand,': 0.97
To Tim Peters <tim.peters@gmail.com>
cc Laura Creighton <lac@openend.se>, Python-List <python-list@python.org>, datetime-sig <datetime-sig@python.org>, lac@openend.se
From Laura Creighton <lac@openend.se>
Subject Re: [Datetime-SIG] Are there any "correct" implementations of tzinfo?
In-reply-to <CAExdVN=RPPVUYWpAUwHWpvy0vMz7zbjFHawYxYfDwuhbFM8B+A@mail.gmail.com>
References <m2h9mzqyy7.fsf@fastmail.com> <CAExdVNm0rrxhbSONfQdor7e=9t+6Tg3hh6eFq-h0NnfdpteVYg@mail.gmail.com> <1442085362.324875.381920729.5E7A6DCE@webmail.messagingengine.com> <CAExdVNnUwRKN2q=trpnD9=mxnXvuosWKO+s5=PCfjAO45-Yugw@mail.gmail.com> <CAP7h-xYFAggqbJBNCZbYFwUqCPzW7-4Rc0x_SzgAumpFYAr6oA@mail.gmail.com> <CAExdVNmfTsqunRR_b-Q1YqWrTjsV1L5ppAoAnL7SUwgR2PFU0A@mail.gmail.com> <CAP7h-xbqq2Eu+vVO2g4WmbRJ=gmL1r9D2sWhKe=qQ8Ev-n415w@mail.gmail.com> <CAP7+vJ+1Vg21qOWAD+9R2REDnWiW4o6nj=Rh8fx3x3cAZipcdw@mail.gmail.com> <CAP7h-xbA6ZagKj+rQ_cCc8d0oK1F329AAhSjY240iiDyB4756A@mail.gmail.com> <CAExdVNnw6zfJQ_wFOurjj6kcLcbr9RgXA7kvyNPmgraMcHU4vQ@mail.gmail.com> <CAP7h-xYp=MsOcvFXNCHNkXDDGH=jcAwYSSw1WWchy5bwZKjwLA@mail.gmail.com> <201509131224.t8DCOXHO004891@fido.openend.se> <CAExdVNkN465=bWeY61PFAxpiUQ-u0p2zaqtwH8PQWyQO4Jw9Mg@mail.gmail.com> <201509131600.t8DG07e0025688@fido.openend.se> <CAExdVNm3e43mJ3tqcUc9175WssV4zeuO024svJbMTjrTab=Qew@mail.gmail.com> <CAExdVN=RPPVUYWpAUwHWpvy0vMz7zbjFHawYxYfDwuhbFM8B+A@mail.gmail.com>
Comments In-reply-to Tim Peters <tim.peters@gmail.com> message dated "Sun, 13 Sep 2015 15:13:53 -0500."
MIME-Version 1.0
Content-Type text/plain; charset="us-ascii"
Content-ID <28025.1442176289.1@fido>
Date Sun, 13 Sep 2015 22:31:29 +0200
X-Greylist Sender IP whitelisted, not delayed by milter-greylist-4.3.9 (theraft.openend.se [82.96.5.2]); Sun, 13 Sep 2015 22:31:31 +0200 (CEST)
X-BeenThere python-list@python.org
X-Mailman-Version 2.1.20+
Precedence list
List-Id General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive <http://mail.python.org/pipermail/python-list/>
List-Post <mailto:python-list@python.org>
List-Help <mailto:python-list-request@python.org?subject=help>
List-Subscribe <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups comp.lang.python
Message-ID <mailman.498.1442176304.8327.python-list@python.org> (permalink)
Lines 42
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1442176304 news.xs4all.nl 23772 [2001:888:2000:d::a6]:47955
X-Complaints-To abuse@xs4all.nl
X-Received-Bytes 7155
X-Received-Body-CRC 562641544
Xref csiph.com comp.lang.python:96526

Show key headers only | View raw


In a message of Sun, 13 Sep 2015 15:13:53 -0500, Tim Peters writes:
>[Laura]
>> Via Rail will give you a schedule when you book your tickets.  But I
>> am wrong, it gives it to you in local time, which you can scrape or
>> even use the via rail api.  So it is the person getting off in
>> Creighton who wants to tell his relatives back in Halifax what
>> time he is arriving (in their time) (so they can call him and
>> avoid the hellish hotel surtax on long distance calls) who will
>> have the problem.
>
>Whatever time zone the traveler's railroad schedule uses, so long as
>it sticks to just one

This is what does not happen.  Which is why I have written a python
app to perform conversions for my parents, in the past.

>But there's nothing new here:  datetime has been around for a dozen
>years already, and nobody is proposing to add any new basic
>functionality to tzinfos.  PEP 495 is only about adding a flag to
>allow correct conversion of ambiguous local times (typically at the
>end of DST, when the local clock repeats a span of times) to UTC.  So
>if this were a popular use case, I expect we would already have heard
>of it.  Note that Python zoneinfo wrappings are already available via,
>at least, the pytz and dateutil packages.

I am a happy user of pytz.  On the other hand, I think this means that
my brain has gone through some sort of non-reversible transformation
which makes me accurate, but not exactly sane on the issue.

I think I have misunderstood Alexander Belopolsky as saying that
datetime had functionality which I don't think it has. Thus I thought
we must be planning to add some functionality here.  Sorry about this.

However, people do need to be aware, if they are not already, that
people with 3 times in 3 different tz will want to sort them.  Telling
them that they must convert them to UTC before they do so is, in my
opinion, a very fine idea. Expecting them to work this out by themselves
via a assertion that the comparison operator is not transitive, is,
I think, asking a lot of them.

Laura

Back to comp.lang.python | Previous | Next | Find similar | Unroll thread


Thread

Re: [Datetime-SIG] Are there any "correct" implementations of tzinfo? Laura Creighton <lac@openend.se> - 2015-09-13 22:31 +0200

csiph-web