Update pytz lib

lib/pytz/LICENSE.txt

@@ -1,19 +0,0 @@
-Copyright (c) 2003-2009 Stuart Bishop <stuart@stuartbishop.net>
-
-Permission is hereby granted, free of charge, to any person obtaining a
-copy of this software and associated documentation files (the "Software"),
-to deal in the Software without restriction, including without limitation
-the rights to use, copy, modify, merge, publish, distribute, sublicense,
-and/or sell copies of the Software, and to permit persons to whom the
-Software is furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in
-all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
-THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-DEALINGS IN THE SOFTWARE.

lib/pytz/README.txt

@@ -1,575 +0,0 @@
-pytz - World Timezone Definitions for Python
-============================================
-
-:Author: Stuart Bishop <stuart@stuartbishop.net>
-
-Introduction
-~~~~~~~~~~~~
-
-pytz brings the Olson tz database into Python. This library allows
-accurate and cross platform timezone calculations using Python 2.4
-or higher. It also solves the issue of ambiguous times at the end
-of daylight saving time, which you can read more about in the Python
-Library Reference (``datetime.tzinfo``).
-
-Almost all of the Olson timezones are supported.
-
-.. note::
-
-    This library differs from the documented Python API for
-    tzinfo implementations; if you want to create local wallclock
-    times you need to use the ``localize()`` method documented in this
-    document. In addition, if you perform date arithmetic on local
-    times that cross DST boundaries, the result may be in an incorrect
-    timezone (ie. subtract 1 minute from 2002-10-27 1:00 EST and you get
-    2002-10-27 0:59 EST instead of the correct 2002-10-27 1:59 EDT). A
-    ``normalize()`` method is provided to correct this. Unfortunately these
-    issues cannot be resolved without modifying the Python datetime
-    implementation (see PEP-431).
-
-
-Installation
-~~~~~~~~~~~~
-
-This package can either be installed from a .egg file using setuptools,
-or from the tarball using the standard Python distutils.
-
-If you are installing from a tarball, run the following command as an
-administrative user::
-
-    python setup.py install
-
-If you are installing using setuptools, you don't even need to download
-anything as the latest version will be downloaded for you
-from the Python package index::
-
-    easy_install --upgrade pytz
-
-If you already have the .egg file, you can use that too::
-
-    easy_install pytz-2008g-py2.6.egg
-
-
-Example & Usage
-~~~~~~~~~~~~~~~
-
-Localized times and date arithmetic
------------------------------------
-
->>> from datetime import datetime, timedelta
->>> from pytz import timezone
->>> import pytz
->>> utc = pytz.utc
->>> utc.zone
-'UTC'
->>> eastern = timezone('US/Eastern')
->>> eastern.zone
-'US/Eastern'
->>> amsterdam = timezone('Europe/Amsterdam')
->>> fmt = '%Y-%m-%d %H:%M:%S %Z%z'
-
-This library only supports two ways of building a localized time. The
-first is to use the ``localize()`` method provided by the pytz library.
-This is used to localize a naive datetime (datetime with no timezone
-information):
-
->>> loc_dt = eastern.localize(datetime(2002, 10, 27, 6, 0, 0))
->>> print(loc_dt.strftime(fmt))
-2002-10-27 06:00:00 EST-0500
-
-The second way of building a localized time is by converting an existing
-localized time using the standard ``astimezone()`` method:
-
->>> ams_dt = loc_dt.astimezone(amsterdam)
->>> ams_dt.strftime(fmt)
-'2002-10-27 12:00:00 CET+0100'
-
-Unfortunately using the tzinfo argument of the standard datetime
-constructors ''does not work'' with pytz for many timezones.
-
->>> datetime(2002, 10, 27, 12, 0, 0, tzinfo=amsterdam).strftime(fmt)
-'2002-10-27 12:00:00 LMT+0020'
-
-It is safe for timezones without daylight saving transitions though, such
-as UTC:
-
->>> datetime(2002, 10, 27, 12, 0, 0, tzinfo=pytz.utc).strftime(fmt)
-'2002-10-27 12:00:00 UTC+0000'
-
-The preferred way of dealing with times is to always work in UTC,
-converting to localtime only when generating output to be read
-by humans.
-
->>> utc_dt = datetime(2002, 10, 27, 6, 0, 0, tzinfo=utc)
->>> loc_dt = utc_dt.astimezone(eastern)
->>> loc_dt.strftime(fmt)
-'2002-10-27 01:00:00 EST-0500'
-
-This library also allows you to do date arithmetic using local
-times, although it is more complicated than working in UTC as you
-need to use the ``normalize()`` method to handle daylight saving time
-and other timezone transitions. In this example, ``loc_dt`` is set
-to the instant when daylight saving time ends in the US/Eastern
-timezone.
-
->>> before = loc_dt - timedelta(minutes=10)
->>> before.strftime(fmt)
-'2002-10-27 00:50:00 EST-0500'
->>> eastern.normalize(before).strftime(fmt)
-'2002-10-27 01:50:00 EDT-0400'
->>> after = eastern.normalize(before + timedelta(minutes=20))
->>> after.strftime(fmt)
-'2002-10-27 01:10:00 EST-0500'
-
-Creating local times is also tricky, and the reason why working with
-local times is not recommended. Unfortunately, you cannot just pass
-a ``tzinfo`` argument when constructing a datetime (see the next
-section for more details)
-
->>> dt = datetime(2002, 10, 27, 1, 30, 0)
->>> dt1 = eastern.localize(dt, is_dst=True)
->>> dt1.strftime(fmt)
-'2002-10-27 01:30:00 EDT-0400'
->>> dt2 = eastern.localize(dt, is_dst=False)
->>> dt2.strftime(fmt)
-'2002-10-27 01:30:00 EST-0500'
-
-Converting between timezones also needs special attention. We also need
-to use the ``normalize()`` method to ensure the conversion is correct.
-
->>> utc_dt = utc.localize(datetime.utcfromtimestamp(1143408899))
->>> utc_dt.strftime(fmt)
-'2006-03-26 21:34:59 UTC+0000'
->>> au_tz = timezone('Australia/Sydney')
->>> au_dt = au_tz.normalize(utc_dt.astimezone(au_tz))
->>> au_dt.strftime(fmt)
-'2006-03-27 08:34:59 AEDT+1100'
->>> utc_dt2 = utc.normalize(au_dt.astimezone(utc))
->>> utc_dt2.strftime(fmt)
-'2006-03-26 21:34:59 UTC+0000'
-
-You can take shortcuts when dealing with the UTC side of timezone
-conversions. ``normalize()`` and ``localize()`` are not really
-necessary when there are no daylight saving time transitions to
-deal with.
-
->>> utc_dt = datetime.utcfromtimestamp(1143408899).replace(tzinfo=utc)
->>> utc_dt.strftime(fmt)
-'2006-03-26 21:34:59 UTC+0000'
->>> au_tz = timezone('Australia/Sydney')
->>> au_dt = au_tz.normalize(utc_dt.astimezone(au_tz))
->>> au_dt.strftime(fmt)
-'2006-03-27 08:34:59 AEDT+1100'
->>> utc_dt2 = au_dt.astimezone(utc)
->>> utc_dt2.strftime(fmt)
-'2006-03-26 21:34:59 UTC+0000'
-
-
-``tzinfo`` API
---------------
-
-The ``tzinfo`` instances returned by the ``timezone()`` function have
-been extended to cope with ambiguous times by adding an ``is_dst``
-parameter to the ``utcoffset()``, ``dst()`` && ``tzname()`` methods.
-
->>> tz = timezone('America/St_Johns')
-
->>> normal = datetime(2009, 9, 1)
->>> ambiguous = datetime(2009, 10, 31, 23, 30)
-
-The ``is_dst`` parameter is ignored for most timestamps. It is only used
-during DST transition ambiguous periods to resulve that ambiguity.
-
->>> tz.utcoffset(normal, is_dst=True)
-datetime.timedelta(-1, 77400)
->>> tz.dst(normal, is_dst=True)
-datetime.timedelta(0, 3600)
->>> tz.tzname(normal, is_dst=True)
-'NDT'
-
->>> tz.utcoffset(ambiguous, is_dst=True)
-datetime.timedelta(-1, 77400)
->>> tz.dst(ambiguous, is_dst=True)
-datetime.timedelta(0, 3600)
->>> tz.tzname(ambiguous, is_dst=True)
-'NDT'
-
->>> tz.utcoffset(normal, is_dst=False)
-datetime.timedelta(-1, 77400)
->>> tz.dst(normal, is_dst=False)
-datetime.timedelta(0, 3600)
->>> tz.tzname(normal, is_dst=False)
-'NDT'
-
->>> tz.utcoffset(ambiguous, is_dst=False)
-datetime.timedelta(-1, 73800)
->>> tz.dst(ambiguous, is_dst=False)
-datetime.timedelta(0)
->>> tz.tzname(ambiguous, is_dst=False)
-'NST'
-
-If ``is_dst`` is not specified, ambiguous timestamps will raise
-an ``pytz.exceptions.AmbiguousTimeError`` exception.
-
->>> tz.utcoffset(normal)
-datetime.timedelta(-1, 77400)
->>> tz.dst(normal)
-datetime.timedelta(0, 3600)
->>> tz.tzname(normal)
-'NDT'
-
->>> import pytz.exceptions
->>> try:
-...     tz.utcoffset(ambiguous)
-... except pytz.exceptions.AmbiguousTimeError:
-...     print('pytz.exceptions.AmbiguousTimeError: %s' % ambiguous)
-pytz.exceptions.AmbiguousTimeError: 2009-10-31 23:30:00
->>> try:
-...     tz.dst(ambiguous)
-... except pytz.exceptions.AmbiguousTimeError:
-...     print('pytz.exceptions.AmbiguousTimeError: %s' % ambiguous)
-pytz.exceptions.AmbiguousTimeError: 2009-10-31 23:30:00
->>> try:
-...     tz.tzname(ambiguous)
-... except pytz.exceptions.AmbiguousTimeError:
-...     print('pytz.exceptions.AmbiguousTimeError: %s' % ambiguous)
-pytz.exceptions.AmbiguousTimeError: 2009-10-31 23:30:00
-
-
-Problems with Localtime
-~~~~~~~~~~~~~~~~~~~~~~~
-
-The major problem we have to deal with is that certain datetimes
-may occur twice in a year. For example, in the US/Eastern timezone
-on the last Sunday morning in October, the following sequence
-happens:
-
-    - 01:00 EDT occurs
-    - 1 hour later, instead of 2:00am the clock is turned back 1 hour
-      and 01:00 happens again (this time 01:00 EST)
-
-In fact, every instant between 01:00 and 02:00 occurs twice. This means
-that if you try and create a time in the 'US/Eastern' timezone
-the standard datetime syntax, there is no way to specify if you meant
-before of after the end-of-daylight-saving-time transition. Using the
-pytz custom syntax, the best you can do is make an educated guess:
-
->>> loc_dt = eastern.localize(datetime(2002, 10, 27, 1, 30, 00))
->>> loc_dt.strftime(fmt)
-'2002-10-27 01:30:00 EST-0500'
-
-As you can see, the system has chosen one for you and there is a 50%
-chance of it being out by one hour. For some applications, this does
-not matter. However, if you are trying to schedule meetings with people
-in different timezones or analyze log files it is not acceptable. 
-
-The best and simplest solution is to stick with using UTC.  The pytz
-package encourages using UTC for internal timezone representation by
-including a special UTC implementation based on the standard Python
-reference implementation in the Python documentation.
-
-The UTC timezone unpickles to be the same instance, and pickles to a
-smaller size than other pytz tzinfo instances.  The UTC implementation
-can be obtained as pytz.utc, pytz.UTC, or pytz.timezone('UTC').
-
->>> import pickle, pytz
->>> dt = datetime(2005, 3, 1, 14, 13, 21, tzinfo=utc)
->>> naive = dt.replace(tzinfo=None)
->>> p = pickle.dumps(dt, 1)
->>> naive_p = pickle.dumps(naive, 1)
->>> len(p) - len(naive_p)
-17
->>> new = pickle.loads(p)
->>> new == dt
-True
->>> new is dt
-False
->>> new.tzinfo is dt.tzinfo
-True
->>> pytz.utc is pytz.UTC is pytz.timezone('UTC')
-True
-
-Note that some other timezones are commonly thought of as the same (GMT,
-Greenwich, Universal, etc.). The definition of UTC is distinct from these
-other timezones, and they are not equivalent. For this reason, they will
-not compare the same in Python.
-
->>> utc == pytz.timezone('GMT')
-False
-
-See the section `What is UTC`_, below.
-
-If you insist on working with local times, this library provides a
-facility for constructing them unambiguously:
-
->>> loc_dt = datetime(2002, 10, 27, 1, 30, 00)
->>> est_dt = eastern.localize(loc_dt, is_dst=True)
->>> edt_dt = eastern.localize(loc_dt, is_dst=False)
->>> print(est_dt.strftime(fmt) + ' / ' + edt_dt.strftime(fmt))
-2002-10-27 01:30:00 EDT-0400 / 2002-10-27 01:30:00 EST-0500
-
-If you pass None as the is_dst flag to localize(), pytz will refuse to
-guess and raise exceptions if you try to build ambiguous or non-existent
-times.
-
-For example, 1:30am on 27th Oct 2002 happened twice in the US/Eastern
-timezone when the clocks where put back at the end of Daylight Saving
-Time:
-
->>> dt = datetime(2002, 10, 27, 1, 30, 00)
->>> try:
-...     eastern.localize(dt, is_dst=None)
-... except pytz.exceptions.AmbiguousTimeError:
-...     print('pytz.exceptions.AmbiguousTimeError: %s' % dt)
-pytz.exceptions.AmbiguousTimeError: 2002-10-27 01:30:00
-
-Similarly, 2:30am on 7th April 2002 never happened at all in the
-US/Eastern timezone, as the clocks where put forward at 2:00am skipping
-the entire hour:
-
->>> dt = datetime(2002, 4, 7, 2, 30, 00)
->>> try:
-...     eastern.localize(dt, is_dst=None)
-... except pytz.exceptions.NonExistentTimeError:
-...     print('pytz.exceptions.NonExistentTimeError: %s' % dt)
-pytz.exceptions.NonExistentTimeError: 2002-04-07 02:30:00
-
-Both of these exceptions share a common base class to make error handling
-easier:
-
->>> isinstance(pytz.AmbiguousTimeError(), pytz.InvalidTimeError)
-True
->>> isinstance(pytz.NonExistentTimeError(), pytz.InvalidTimeError)
-True
-
-
-A special case is where countries change their timezone definitions
-with no daylight savings time switch. For example, in 1915 Warsaw
-switched from Warsaw time to Central European time with no daylight savings
-transition. So at the stroke of midnight on August 5th 1915 the clocks
-were wound back 24 minutes creating an ambiguous time period that cannot
-be specified without referring to the timezone abbreviation or the
-actual UTC offset. In this case midnight happened twice, neither time
-during a daylight saving time period. pytz handles this transition by
-treating the ambiguous period before the switch as daylight savings
-time, and the ambiguous period after as standard time.
-
-
->>> warsaw = pytz.timezone('Europe/Warsaw')
->>> amb_dt1 = warsaw.localize(datetime(1915, 8, 4, 23, 59, 59), is_dst=True)
->>> amb_dt1.strftime(fmt)
-'1915-08-04 23:59:59 WMT+0124'
->>> amb_dt2 = warsaw.localize(datetime(1915, 8, 4, 23, 59, 59), is_dst=False)
->>> amb_dt2.strftime(fmt)
-'1915-08-04 23:59:59 CET+0100'
->>> switch_dt = warsaw.localize(datetime(1915, 8, 5, 00, 00, 00), is_dst=False)
->>> switch_dt.strftime(fmt)
-'1915-08-05 00:00:00 CET+0100'
->>> str(switch_dt - amb_dt1)
-'0:24:01'
->>> str(switch_dt - amb_dt2)
-'0:00:01'
-
-The best way of creating a time during an ambiguous time period is
-by converting from another timezone such as UTC:
-
->>> utc_dt = datetime(1915, 8, 4, 22, 36, tzinfo=pytz.utc)
->>> utc_dt.astimezone(warsaw).strftime(fmt)
-'1915-08-04 23:36:00 CET+0100'
-
-The standard Python way of handling all these ambiguities is not to
-handle them, such as demonstrated in this example using the US/Eastern
-timezone definition from the Python documentation (Note that this
-implementation only works for dates between 1987 and 2006 - it is
-included for tests only!):
-
->>> from pytz.reference import Eastern # pytz.reference only for tests
->>> dt = datetime(2002, 10, 27, 0, 30, tzinfo=Eastern)
->>> str(dt)
-'2002-10-27 00:30:00-04:00'
->>> str(dt + timedelta(hours=1))
-'2002-10-27 01:30:00-05:00'
->>> str(dt + timedelta(hours=2))
-'2002-10-27 02:30:00-05:00'
->>> str(dt + timedelta(hours=3))
-'2002-10-27 03:30:00-05:00'
-
-Notice the first two results? At first glance you might think they are
-correct, but taking the UTC offset into account you find that they are
-actually two hours appart instead of the 1 hour we asked for.
-
->>> from pytz.reference import UTC # pytz.reference only for tests
->>> str(dt.astimezone(UTC))
-'2002-10-27 04:30:00+00:00'
->>> str((dt + timedelta(hours=1)).astimezone(UTC))
-'2002-10-27 06:30:00+00:00'
-
-
-Country Information
-~~~~~~~~~~~~~~~~~~~
-
-A mechanism is provided to access the timezones commonly in use
-for a particular country, looked up using the ISO 3166 country code.
-It returns a list of strings that can be used to retrieve the relevant
-tzinfo instance using ``pytz.timezone()``:
-
->>> print(' '.join(pytz.country_timezones['nz']))
-Pacific/Auckland Pacific/Chatham
-
-The Olson database comes with a ISO 3166 country code to English country
-name mapping that pytz exposes as a dictionary:
-
->>> print(pytz.country_names['nz'])
-New Zealand
-
-
-What is UTC
-~~~~~~~~~~~
-
-'UTC' is `Coordinated Universal Time`_. It is a successor to, but distinct
-from, Greenwich Mean Time (GMT) and the various definitions of Universal
-Time. UTC is now the worldwide standard for regulating clocks and time
-measurement.
-
-All other timezones are defined relative to UTC, and include offsets like
-UTC+0800 - hours to add or subtract from UTC to derive the local time. No
-daylight saving time occurs in UTC, making it a useful timezone to perform
-date arithmetic without worrying about the confusion and ambiguities caused
-by daylight saving time transitions, your country changing its timezone, or
-mobile computers that roam through multiple timezones.
-
-..  _Coordinated Universal Time: https://en.wikipedia.org/wiki/Coordinated_Universal_Time
-
-
-Helpers
-~~~~~~~
-
-There are two lists of timezones provided.
-
-``all_timezones`` is the exhaustive list of the timezone names that can
-be used.
-
->>> from pytz import all_timezones
->>> len(all_timezones) >= 500
-True
->>> 'Etc/Greenwich' in all_timezones
-True
-
-``common_timezones`` is a list of useful, current timezones. It doesn't
-contain deprecated zones or historical zones, except for a few I've
-deemed in common usage, such as US/Eastern (open a bug report if you
-think other timezones are deserving of being included here). It is also
-a sequence of strings.
-
->>> from pytz import common_timezones
->>> len(common_timezones) < len(all_timezones)
-True
->>> 'Etc/Greenwich' in common_timezones
-False
->>> 'Australia/Melbourne' in common_timezones
-True
->>> 'US/Eastern' in common_timezones
-True
->>> 'Canada/Eastern' in common_timezones
-True
->>> 'US/Pacific-New' in all_timezones
-True
->>> 'US/Pacific-New' in common_timezones
-False
-
-Both ``common_timezones`` and ``all_timezones`` are alphabetically
-sorted:
-
->>> common_timezones_dupe = common_timezones[:]
->>> common_timezones_dupe.sort()
->>> common_timezones == common_timezones_dupe
-True
->>> all_timezones_dupe = all_timezones[:]
->>> all_timezones_dupe.sort()
->>> all_timezones == all_timezones_dupe
-True
-
-``all_timezones`` and ``common_timezones`` are also available as sets.
-
->>> from pytz import all_timezones_set, common_timezones_set
->>> 'US/Eastern' in all_timezones_set
-True
->>> 'US/Eastern' in common_timezones_set
-True
->>> 'Australia/Victoria' in common_timezones_set
-False
-
-You can also retrieve lists of timezones used by particular countries
-using the ``country_timezones()`` function. It requires an ISO-3166
-two letter country code.
-
->>> from pytz import country_timezones
->>> print(' '.join(country_timezones('ch')))
-Europe/Zurich
->>> print(' '.join(country_timezones('CH')))
-Europe/Zurich
-
-
-License
-~~~~~~~
-
-MIT license.
-
-This code is also available as part of Zope 3 under the Zope Public
-License,  Version 2.1 (ZPL).
-
-I'm happy to relicense this code if necessary for inclusion in other
-open source projects.
-
-
-Latest Versions
-~~~~~~~~~~~~~~~
-
-This package will be updated after releases of the Olson timezone
-database.  The latest version can be downloaded from the `Python Package
-Index <http://pypi.python.org/pypi/pytz/>`_.  The code that is used
-to generate this distribution is hosted on launchpad.net and available
-using the `Bazaar version control system <http://bazaar-vcs.org>`_
-using::
-
-    bzr branch lp:pytz
-
-Announcements of new releases are made on
-`Launchpad <https://launchpad.net/pytz>`_, and the
-`Atom feed <http://feeds.launchpad.net/pytz/announcements.atom>`_
-hosted there.
-
-
-Bugs, Feature Requests & Patches
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Bugs can be reported using `Launchpad <https://bugs.launchpad.net/pytz>`_.
-
-
-Issues & Limitations
-~~~~~~~~~~~~~~~~~~~~
-
-- Offsets from UTC are rounded to the nearest whole minute, so timezones
-  such as Europe/Amsterdam pre 1937 will be up to 30 seconds out. This
-  is a limitation of the Python datetime library.
-
-- If you think a timezone definition is incorrect, I probably can't fix
-  it. pytz is a direct translation of the Olson timezone database, and
-  changes to the timezone definitions need to be made to this source.
-  If you find errors they should be reported to the time zone mailing
-  list, linked from http://www.iana.org/time-zones.
-
-
-Further Reading
-~~~~~~~~~~~~~~~
-
-More info than you want to know about timezones:
-http://www.twinsun.com/tz/tz-link.htm
-
-
-Contact
-~~~~~~~
-
-Stuart Bishop <stuart@stuartbishop.net>
-
-

lib/pytz/__init__.py

@@ -8,12 +8,25 @@ See the datetime section of the Python Library Reference for information
 on how to use these modules.
 '''
 
-# The Olson database is updated several times a year.
-OLSON_VERSION = '2014j'
-VERSION = '2014.10'  # Switching to pip compatible version numbering.
+import sys
+import datetime
+import os.path
+
+from pytz.exceptions import AmbiguousTimeError
+from pytz.exceptions import InvalidTimeError
+from pytz.exceptions import NonExistentTimeError
+from pytz.exceptions import UnknownTimeZoneError
+from pytz.lazy import LazyDict, LazyList, LazySet  # noqa
+from pytz.tzinfo import unpickler, BaseTzInfo
+from pytz.tzfile import build_tzinfo
+
+
+# The IANA (nee Olson) database is updated several times a year.
+OLSON_VERSION = '2021c'
+VERSION = '2021.3'  # pip compatible version number.
 __version__ = VERSION
 
-OLSEN_VERSION = OLSON_VERSION # Old releases had this misspelling
+OLSEN_VERSION = OLSON_VERSION  # Old releases had this misspelling
 
 __all__ = [
     'timezone', 'utc', 'country_timezones', 'country_names',
@@ -21,32 +34,15 @@ __all__ = [
     'NonExistentTimeError', 'UnknownTimeZoneError',
     'all_timezones', 'all_timezones_set',
     'common_timezones', 'common_timezones_set',
-    ]
-
-import sys, datetime, os.path, gettext
-
-try:
-    from pkg_resources import resource_stream
-except ImportError:
-    resource_stream = None
-
-from pytz.exceptions import AmbiguousTimeError
-from pytz.exceptions import InvalidTimeError
-from pytz.exceptions import NonExistentTimeError
-from pytz.exceptions import UnknownTimeZoneError
-from pytz.lazy import LazyDict, LazyList, LazySet
-from pytz.tzinfo import unpickler
-from pytz.tzfile import build_tzinfo, _byte_string
+    'BaseTzInfo', 'FixedOffset',
+]
 
 
-try:
-    str
-
-except NameError: # Python 3.x
+if sys.version_info[0] > 2:  # Python 3.x
 
     # Python 3.x doesn't have unicode(), making writing code
     # for Python 2.3 and Python 3.x a pain.
-    str = str
+    unicode = str
 
     def ascii(s):
         r"""
@@ -57,10 +53,13 @@ except NameError: # Python 3.x
             ...
         UnicodeEncodeError: ...
         """
-        s.encode('US-ASCII') # Raise an exception if not ASCII
-        return s # But return the original string - not a byte string.
+        if type(s) == bytes:
+            s = s.decode('ASCII')
+        else:
+            s.encode('ASCII')  # Raise an exception if not ASCII
+        return s  # But the string - not a byte string.
 
-else: # Python 2.x
+else:  # Python 2.x
 
     def ascii(s):
         r"""
@@ -73,7 +72,7 @@ else: # Python 2.x
             ...
         UnicodeEncodeError: ...
         """
-        return s.encode('US-ASCII')
+        return s.encode('ASCII')
 
 
 def open_resource(name):
@@ -81,49 +80,55 @@ def open_resource(name):
 
     Uses the pkg_resources module if available and no standard file
     found at the calculated location.
+
+    It is possible to specify different location for zoneinfo
+    subdir by using the PYTZ_TZDATADIR environment variable.
     """
     name_parts = name.lstrip('/').split('/')
     for part in name_parts:
         if part == os.path.pardir or os.path.sep in part:
             raise ValueError('Bad path segment: %r' % part)
-    filename = os.path.join(os.path.dirname(__file__),
-                            'zoneinfo', *name_parts)
-    if not os.path.exists(filename) and resource_stream is not None:
-        # http://bugs.launchpad.net/bugs/383171 - we avoid using this
-        # unless absolutely necessary to help when a broken version of
-        # pkg_resources is installed.
-        return resource_stream(__name__, 'zoneinfo/' + name)
+    zoneinfo_dir = os.environ.get('PYTZ_TZDATADIR', None)
+    if zoneinfo_dir is not None:
+        filename = os.path.join(zoneinfo_dir, *name_parts)
+    else:
+        filename = os.path.join(os.path.dirname(__file__),
+                                'zoneinfo', *name_parts)
+        if not os.path.exists(filename):
+            # http://bugs.launchpad.net/bugs/383171 - we avoid using this
+            # unless absolutely necessary to help when a broken version of
+            # pkg_resources is installed.
+            try:
+                from pkg_resources import resource_stream
+            except ImportError:
+                resource_stream = None
+
+            if resource_stream is not None:
+                return resource_stream(__name__, 'zoneinfo/' + name)
     return open(filename, 'rb')
 
 
 def resource_exists(name):
     """Return true if the given resource exists"""
     try:
+        if os.environ.get('PYTZ_SKIPEXISTSCHECK', ''):
+            # In "standard" distributions, we can assume that
+            # all the listed timezones are present. As an
+            # import-speed optimization, you can set the
+            # PYTZ_SKIPEXISTSCHECK flag to skip checking
+            # for the presence of the resource file on disk.
+            return True
         open_resource(name).close()
         return True
     except IOError:
         return False
 
 
-# Enable this when we get some translations?
-# We want an i18n API that is useful to programs using Python's gettext
-# module, as well as the Zope3 i18n package. Perhaps we should just provide
-# the POT file and translations, and leave it up to callers to make use
-# of them.
-# 
-# t = gettext.translation(
-#         'pytz', os.path.join(os.path.dirname(__file__), 'locales'),
-#         fallback=True
-#         )
-# def _(timezone_name):
-#     """Translate a timezone name using the current locale, returning Unicode"""
-#     return t.ugettext(timezone_name)
-
-
 _tzinfo_cache = {}
 
+
 def timezone(zone):
-    r''' Return a datetime.tzinfo implementation for the given timezone 
+    r''' Return a datetime.tzinfo implementation for the given timezone
 
     >>> from datetime import datetime, timedelta
     >>> utc = timezone('UTC')
@@ -159,6 +164,9 @@ def timezone(zone):
     Unknown
 
     '''
+    if zone is None:
+        raise UnknownTimeZoneError(None)
+
     if zone.upper() == 'UTC':
         return utc
 
@@ -168,9 +176,9 @@ def timezone(zone):
         # All valid timezones are ASCII
         raise UnknownTimeZoneError(zone)
 
-    zone = _unmunge_zone(zone)
+    zone = _case_insensitive_zone_lookup(_unmunge_zone(zone))
     if zone not in _tzinfo_cache:
-        if zone in all_timezones_set:
+        if zone in all_timezones_set:  # noqa
             fp = open_resource(zone)
             try:
                 _tzinfo_cache[zone] = build_tzinfo(zone, fp)
@@ -187,11 +195,22 @@ def _unmunge_zone(zone):
     return zone.replace('_plus_', '+').replace('_minus_', '-')
 
 
+_all_timezones_lower_to_standard = None
+
+
+def _case_insensitive_zone_lookup(zone):
+    """case-insensitively matching timezone, else return zone unchanged"""
+    global _all_timezones_lower_to_standard
+    if _all_timezones_lower_to_standard is None:
+        _all_timezones_lower_to_standard = dict((tz.lower(), tz) for tz in all_timezones)  # noqa
+    return _all_timezones_lower_to_standard.get(zone.lower()) or zone  # noqa
+
+
 ZERO = datetime.timedelta(0)
 HOUR = datetime.timedelta(hours=1)
 
 
-class UTC(datetime.tzinfo):
+class UTC(BaseTzInfo):
     """UTC
 
     Optimized UTC implementation. It unpickles using the single module global
@@ -241,18 +260,18 @@ class UTC(datetime.tzinfo):
         return "UTC"
 
 
-UTC = utc = UTC() # UTC is a singleton
+UTC = utc = UTC()  # UTC is a singleton
 
 
 def _UTC():
     """Factory function for utc unpickling.
 
-    Makes sure that unpickling a utc instance always returns the same 
+    Makes sure that unpickling a utc instance always returns the same
     module global.
 
     These examples belong in the UTC class above, but it is obscured; or in
-    the README.txt, but we are not depending on Python 2.4 so integrating
-    the README.txt examples with the unit tests is not trivial.
+    the README.rst, but we are not depending on Python 2.4 so integrating
+    the README.rst examples with the unit tests is not trivial.
 
     >>> import datetime, pickle
     >>> dt = datetime.datetime(2005, 3, 1, 14, 13, 21, tzinfo=utc)
@@ -274,6 +293,8 @@ def _UTC():
     False
     """
     return utc
+
+
 _UTC.__safe_for_unpickling__ = True
 
 
@@ -284,9 +305,10 @@ def _p(*args):
     by shortening the path.
     """
     return unpickler(*args)
-_p.__safe_for_unpickling__ = True
 
 
+_p.__safe_for_unpickling__ = True
+
 
 class _CountryTimezoneDict(LazyDict):
     """Map ISO 3166 country code to a list of timezone names commonly used
@@ -329,11 +351,11 @@ class _CountryTimezoneDict(LazyDict):
         zone_tab = open_resource('zone.tab')
         try:
             for line in zone_tab:
-                line = line.decode('US-ASCII')
+                line = line.decode('UTF-8')
                 if line.startswith('#'):
                     continue
                 code, coordinates, zone = line.split(None, 4)[:3]
-                if zone not in all_timezones_set:
+                if zone not in all_timezones_set:  # noqa
                     continue
                 try:
                     data[code].append(zone)
@@ -343,6 +365,7 @@ class _CountryTimezoneDict(LazyDict):
         finally:
             zone_tab.close()
 
+
 country_timezones = _CountryTimezoneDict()
 
 
@@ -357,7 +380,7 @@ class _CountryNameDict(LazyDict):
         zone_tab = open_resource('iso3166.tab')
         try:
             for line in zone_tab.readlines():
-                line = line.decode('US-ASCII')
+                line = line.decode('UTF-8')
                 if line.startswith('#'):
                     continue
                 code, name = line.split(None, 1)
@@ -366,6 +389,7 @@ class _CountryNameDict(LazyDict):
         finally:
             zone_tab.close()
 
+
 country_names = _CountryNameDict()
 
 
@@ -373,7 +397,7 @@ country_names = _CountryNameDict()
 
 class _FixedOffset(datetime.tzinfo):
 
-    zone = None # to match the standard pytz API
+    zone = None  # to match the standard pytz API
 
     def __init__(self, minutes):
         if abs(minutes) >= 1440:
@@ -404,29 +428,31 @@ class _FixedOffset(datetime.tzinfo):
 
     def normalize(self, dt, is_dst=False):
         '''Correct the timezone information on the given datetime'''
+        if dt.tzinfo is self:
+            return dt
         if dt.tzinfo is None:
             raise ValueError('Naive time - no tzinfo set')
-        return dt.replace(tzinfo=self)
+        return dt.astimezone(self)
 
 
-def FixedOffset(offset, _tzinfos = {}):
+def FixedOffset(offset, _tzinfos={}):
     """return a fixed-offset timezone based off a number of minutes.
 
         >>> one = FixedOffset(-330)
         >>> one
         pytz.FixedOffset(-330)
-        >>> one.utcoffset(datetime.datetime.now())
-        datetime.timedelta(-1, 66600)
-        >>> one.dst(datetime.datetime.now())
-        datetime.timedelta(0)
+        >>> str(one.utcoffset(datetime.datetime.now()))
+        '-1 day, 18:30:00'
+        >>> str(one.dst(datetime.datetime.now()))
+        '0:00:00'
 
         >>> two = FixedOffset(1380)
         >>> two
         pytz.FixedOffset(1380)
-        >>> two.utcoffset(datetime.datetime.now())
-        datetime.timedelta(0, 82800)
-        >>> two.dst(datetime.datetime.now())
-        datetime.timedelta(0)
+        >>> str(two.utcoffset(datetime.datetime.now()))
+        '23:00:00'
+        >>> str(two.dst(datetime.datetime.now()))
+        '0:00:00'
 
     The datetime.timedelta must be between the range of -1 and 1 day,
     non-inclusive.
@@ -475,18 +501,19 @@ def FixedOffset(offset, _tzinfos = {}):
 
     return info
 
+
 FixedOffset.__safe_for_unpickling__ = True
 
 
 def _test():
-    import doctest, os, sys
+    import doctest
     sys.path.insert(0, os.pardir)
     import pytz
     return doctest.testmod(pytz)
 
+
 if __name__ == '__main__':
     _test()
-
 all_timezones = \
 ['Africa/Abidjan',
  'Africa/Accra',
@@ -599,6 +626,7 @@ all_timezones = \
  'America/Eirunepe',
  'America/El_Salvador',
  'America/Ensenada',
+ 'America/Fort_Nelson',
  'America/Fort_Wayne',
  'America/Fortaleza',
  'America/Glace_Bay',
@@ -662,6 +690,7 @@ all_timezones = \
  'America/North_Dakota/Beulah',
  'America/North_Dakota/Center',
  'America/North_Dakota/New_Salem',
+ 'America/Nuuk',
  'America/Ojinaga',
  'America/Panama',
  'America/Pangnirtung',
@@ -672,6 +701,7 @@ all_timezones = \
  'America/Porto_Acre',
  'America/Porto_Velho',
  'America/Puerto_Rico',
+ 'America/Punta_Arenas',
  'America/Rainy_River',
  'America/Rankin_Inlet',
  'America/Recife',
@@ -727,10 +757,12 @@ all_timezones = \
  'Asia/Aqtobe',
  'Asia/Ashgabat',
  'Asia/Ashkhabad',
+ 'Asia/Atyrau',
  'Asia/Baghdad',
  'Asia/Bahrain',
  'Asia/Baku',
  'Asia/Bangkok',
+ 'Asia/Barnaul',
  'Asia/Beirut',
  'Asia/Bishkek',
  'Asia/Brunei',
@@ -746,6 +778,7 @@ all_timezones = \
  'Asia/Dili',
  'Asia/Dubai',
  'Asia/Dushanbe',
+ 'Asia/Famagusta',
  'Asia/Gaza',
  'Asia/Harbin',
  'Asia/Hebron',
@@ -784,6 +817,7 @@ all_timezones = \
  'Asia/Pontianak',
  'Asia/Pyongyang',
  'Asia/Qatar',
+ 'Asia/Qostanay',
  'Asia/Qyzylorda',
  'Asia/Rangoon',
  'Asia/Riyadh',
@@ -802,6 +836,7 @@ all_timezones = \
  'Asia/Thimbu',
  'Asia/Thimphu',
  'Asia/Tokyo',
+ 'Asia/Tomsk',
  'Asia/Ujung_Pandang',
  'Asia/Ulaanbaatar',
  'Asia/Ulan_Bator',
@@ -810,6 +845,7 @@ all_timezones = \
  'Asia/Vientiane',
  'Asia/Vladivostok',
  'Asia/Yakutsk',
+ 'Asia/Yangon',
  'Asia/Yekaterinburg',
  'Asia/Yerevan',
  'Atlantic/Azores',
@@ -855,7 +891,6 @@ all_timezones = \
  'CST6CDT',
  'Canada/Atlantic',
  'Canada/Central',
- 'Canada/East-Saskatchewan',
  'Canada/Eastern',
  'Canada/Mountain',
  'Canada/Newfoundland',
@@ -907,6 +942,7 @@ all_timezones = \
  'Etc/Zulu',
  'Europe/Amsterdam',
  'Europe/Andorra',
+ 'Europe/Astrakhan',
  'Europe/Athens',
  'Europe/Belfast',
  'Europe/Belgrade',
@@ -927,6 +963,7 @@ all_timezones = \
  'Europe/Jersey',
  'Europe/Kaliningrad',
  'Europe/Kiev',
+ 'Europe/Kirov',
  'Europe/Lisbon',
  'Europe/Ljubljana',
  'Europe/London',
@@ -947,6 +984,7 @@ all_timezones = \
  'Europe/Samara',
  'Europe/San_Marino',
  'Europe/Sarajevo',
+ 'Europe/Saratov',
  'Europe/Simferopol',
  'Europe/Skopje',
  'Europe/Sofia',
@@ -954,6 +992,7 @@ all_timezones = \
  'Europe/Tallinn',
  'Europe/Tirane',
  'Europe/Tiraspol',
+ 'Europe/Ulyanovsk',
  'Europe/Uzhgorod',
  'Europe/Vaduz',
  'Europe/Vatican',
@@ -1019,6 +1058,7 @@ all_timezones = \
  'Pacific/Guam',
  'Pacific/Honolulu',
  'Pacific/Johnston',
+ 'Pacific/Kanton',
  'Pacific/Kiritimati',
  'Pacific/Kosrae',
  'Pacific/Kwajalein',
@@ -1063,7 +1103,6 @@ all_timezones = \
  'US/Michigan',
  'US/Mountain',
  'US/Pacific',
- 'US/Pacific-New',
  'US/Samoa',
  'UTC',
  'Universal',
@@ -1177,9 +1216,9 @@ common_timezones = \
  'America/Edmonton',
  'America/Eirunepe',
  'America/El_Salvador',
+ 'America/Fort_Nelson',
  'America/Fortaleza',
  'America/Glace_Bay',
- 'America/Godthab',
  'America/Goose_Bay',
  'America/Grand_Turk',
  'America/Grenada',
@@ -1224,7 +1263,6 @@ common_timezones = \
  'America/Moncton',
  'America/Monterrey',
  'America/Montevideo',
- 'America/Montreal',
  'America/Montserrat',
  'America/Nassau',
  'America/New_York',
@@ -1234,6 +1272,7 @@ common_timezones = \
  'America/North_Dakota/Beulah',
  'America/North_Dakota/Center',
  'America/North_Dakota/New_Salem',
+ 'America/Nuuk',
  'America/Ojinaga',
  'America/Panama',
  'America/Pangnirtung',
@@ -1243,13 +1282,13 @@ common_timezones = \
  'America/Port_of_Spain',
  'America/Porto_Velho',
  'America/Puerto_Rico',
+ 'America/Punta_Arenas',
  'America/Rainy_River',
  'America/Rankin_Inlet',
  'America/Recife',
  'America/Regina',
  'America/Resolute',
  'America/Rio_Branco',
- 'America/Santa_Isabel',
  'America/Santarem',
  'America/Santiago',
  'America/Santo_Domingo',
@@ -1293,10 +1332,12 @@ common_timezones = \
  'Asia/Aqtau',
  'Asia/Aqtobe',
  'Asia/Ashgabat',
+ 'Asia/Atyrau',
  'Asia/Baghdad',
  'Asia/Bahrain',
  'Asia/Baku',
  'Asia/Bangkok',
+ 'Asia/Barnaul',
  'Asia/Beirut',
  'Asia/Bishkek',
  'Asia/Brunei',
@@ -1308,6 +1349,7 @@ common_timezones = \
  'Asia/Dili',
  'Asia/Dubai',
  'Asia/Dushanbe',
+ 'Asia/Famagusta',
  'Asia/Gaza',
  'Asia/Hebron',
  'Asia/Ho_Chi_Minh',
@@ -1341,8 +1383,8 @@ common_timezones = \
  'Asia/Pontianak',
  'Asia/Pyongyang',
  'Asia/Qatar',
+ 'Asia/Qostanay',
  'Asia/Qyzylorda',
- 'Asia/Rangoon',
  'Asia/Riyadh',
  'Asia/Sakhalin',
  'Asia/Samarkand',
@@ -1356,12 +1398,14 @@ common_timezones = \
  'Asia/Tehran',
  'Asia/Thimphu',
  'Asia/Tokyo',
+ 'Asia/Tomsk',
  'Asia/Ulaanbaatar',
  'Asia/Urumqi',
  'Asia/Ust-Nera',
  'Asia/Vientiane',
  'Asia/Vladivostok',
  'Asia/Yakutsk',
+ 'Asia/Yangon',
  'Asia/Yekaterinburg',
  'Asia/Yerevan',
  'Atlantic/Azores',
@@ -1377,7 +1421,6 @@ common_timezones = \
  'Australia/Adelaide',
  'Australia/Brisbane',
  'Australia/Broken_Hill',
- 'Australia/Currie',
  'Australia/Darwin',
  'Australia/Eucla',
  'Australia/Hobart',
@@ -1394,6 +1437,7 @@ common_timezones = \
  'Canada/Pacific',
  'Europe/Amsterdam',
  'Europe/Andorra',
+ 'Europe/Astrakhan',
  'Europe/Athens',
  'Europe/Belgrade',
  'Europe/Berlin',
@@ -1413,6 +1457,7 @@ common_timezones = \
  'Europe/Jersey',
  'Europe/Kaliningrad',
  'Europe/Kiev',
+ 'Europe/Kirov',
  'Europe/Lisbon',
  'Europe/Ljubljana',
  'Europe/London',
@@ -1432,12 +1477,14 @@ common_timezones = \
  'Europe/Samara',
  'Europe/San_Marino',
  'Europe/Sarajevo',
+ 'Europe/Saratov',
  'Europe/Simferopol',
  'Europe/Skopje',
  'Europe/Sofia',
  'Europe/Stockholm',
  'Europe/Tallinn',
  'Europe/Tirane',
+ 'Europe/Ulyanovsk',
  'Europe/Uzhgorod',
  'Europe/Vaduz',
  'Europe/Vatican',
@@ -1467,7 +1514,6 @@ common_timezones = \
  'Pacific/Chuuk',
  'Pacific/Easter',
  'Pacific/Efate',
- 'Pacific/Enderbury',
  'Pacific/Fakaofo',
  'Pacific/Fiji',
  'Pacific/Funafuti',
@@ -1476,7 +1522,7 @@ common_timezones = \
  'Pacific/Guadalcanal',
  'Pacific/Guam',
  'Pacific/Honolulu',
- 'Pacific/Johnston',
+ 'Pacific/Kanton',
  'Pacific/Kiritimati',
  'Pacific/Kosrae',
  'Pacific/Kwajalein',

lib/pytz/exceptions.py

@@ -5,10 +5,14 @@ Custom exceptions raised by pytz.
 __all__ = [
     'UnknownTimeZoneError', 'InvalidTimeError', 'AmbiguousTimeError',
     'NonExistentTimeError',
-    ]
+]
 
 
-class UnknownTimeZoneError(KeyError):
+class Error(Exception):
+    '''Base class for all exceptions raised by the pytz library'''
+
+
+class UnknownTimeZoneError(KeyError, Error):
     '''Exception raised when pytz is passed an unknown timezone.
 
     >>> isinstance(UnknownTimeZoneError(), LookupError)
@@ -20,11 +24,18 @@ class UnknownTimeZoneError(KeyError):
 
     >>> isinstance(UnknownTimeZoneError(), KeyError)
     True
+
+    And also a subclass of pytz.exceptions.Error, as are other pytz
+    exceptions.
+
+    >>> isinstance(UnknownTimeZoneError(), Error)
+    True
+
     '''
     pass
 
 
-class InvalidTimeError(Exception):
+class InvalidTimeError(Error):
     '''Base class for invalid time exceptions.'''
 
 

lib/pytz/lazy.py

@@ -1,8 +1,11 @@
 from threading import RLock
 try:
-    from UserDict import DictMixin
-except ImportError:
-    from collections import Mapping as DictMixin
+    from collections.abc import Mapping as DictMixin
+except ImportError:  # Python < 3.3
+    try:
+        from UserDict import DictMixin  # Python 2
+    except ImportError:  # Python 3.0-3.3
+        from collections import Mapping as DictMixin
 
 
 # With lazy loading, we might end up with multiple threads triggering
@@ -13,6 +16,7 @@ _fill_lock = RLock()
 class LazyDict(DictMixin):
     """Dictionary populated on first use."""
     data = None
+
     def __getitem__(self, key):
         if self.data is None:
             _fill_lock.acquire()
@@ -61,7 +65,7 @@ class LazyDict(DictMixin):
                     self._fill()
             finally:
                 _fill_lock.release()
-        return list(self.data.keys())
+        return self.data.keys()
 
 
 class LazyList(list):

lib/pytz/reference.py

@@ -5,17 +5,28 @@ Used for testing against as they are only correct for the years
 '''
 
 from datetime import tzinfo, timedelta, datetime
-from pytz import utc, UTC, HOUR, ZERO
+from pytz import HOUR, ZERO, UTC
+
+__all__ = [
+    'FixedOffset',
+    'LocalTimezone',
+    'USTimeZone',
+    'Eastern',
+    'Central',
+    'Mountain',
+    'Pacific',
+    'UTC'
+]
+
 
 # A class building tzinfo objects for fixed-offset time zones.
 # Note that FixedOffset(0, "UTC") is a different way to build a
 # UTC tzinfo object.
-
 class FixedOffset(tzinfo):
     """Fixed offset in minutes east from UTC."""
 
     def __init__(self, offset, name):
-        self.__offset = timedelta(minutes = offset)
+        self.__offset = timedelta(minutes=offset)
         self.__name = name
 
     def utcoffset(self, dt):
@@ -27,18 +38,19 @@ class FixedOffset(tzinfo):
     def dst(self, dt):
         return ZERO
 
-# A class capturing the platform's idea of local time.
 
 import time as _time
 
-STDOFFSET = timedelta(seconds = -_time.timezone)
+STDOFFSET = timedelta(seconds=-_time.timezone)
 if _time.daylight:
-    DSTOFFSET = timedelta(seconds = -_time.altzone)
+    DSTOFFSET = timedelta(seconds=-_time.altzone)
 else:
     DSTOFFSET = STDOFFSET
 
 DSTDIFF = DSTOFFSET - STDOFFSET
 
+
+# A class capturing the platform's idea of local time.
 class LocalTimezone(tzinfo):
 
     def utcoffset(self, dt):
@@ -66,7 +78,6 @@ class LocalTimezone(tzinfo):
 
 Local = LocalTimezone()
 
-# A complete implementation of current DST rules for major US time zones.
 
 def first_sunday_on_or_after(dt):
     days_to_go = 6 - dt.weekday()
@@ -74,12 +85,15 @@ def first_sunday_on_or_after(dt):
         dt += timedelta(days_to_go)
     return dt
 
+
 # In the US, DST starts at 2am (standard time) on the first Sunday in April.
 DSTSTART = datetime(1, 4, 1, 2)
 # and ends at 2am (DST time; 1am standard time) on the last Sunday of Oct.
 # which is the first Sunday on or after Oct 25.
 DSTEND = datetime(1, 10, 25, 1)
 
+
+# A complete implementation of current DST rules for major US time zones.
 class USTimeZone(tzinfo):
 
     def __init__(self, hours, reprname, stdname, dstname):
@@ -120,8 +134,7 @@ class USTimeZone(tzinfo):
         else:
             return ZERO
 
-Eastern  = USTimeZone(-5, "Eastern",  "EST", "EDT")
-Central  = USTimeZone(-6, "Central",  "CST", "CDT")
+Eastern = USTimeZone(-5, "Eastern", "EST", "EDT")
+Central = USTimeZone(-6, "Central", "CST", "CDT")
 Mountain = USTimeZone(-7, "Mountain", "MST", "MDT")
-Pacific  = USTimeZone(-8, "Pacific",  "PST", "PDT")
-
+Pacific = USTimeZone(-8, "Pacific", "PST", "PDT")

lib/pytz/tzfile.py

@@ -1,40 +1,38 @@
-#!/usr/bin/env python
 '''
 $Id: tzfile.py,v 1.8 2004/06/03 00:15:24 zenzen Exp $
 '''
 
-try:
-    from io import StringIO
-except ImportError:
-    from io import StringIO
-from datetime import datetime, timedelta
+from datetime import datetime
 from struct import unpack, calcsize
 
 from pytz.tzinfo import StaticTzInfo, DstTzInfo, memorized_ttinfo
 from pytz.tzinfo import memorized_datetime, memorized_timedelta
 
+
 def _byte_string(s):
     """Cast a string or byte string to an ASCII byte string."""
-    return s.encode('US-ASCII')
+    return s.encode('ASCII')
 
 _NULL = _byte_string('\0')
 
+
 def _std_string(s):
     """Cast a string or byte string to an ASCII string."""
-    return str(s.decode('US-ASCII'))
+    return str(s.decode('ASCII'))
+
 
 def build_tzinfo(zone, fp):
     head_fmt = '>4s c 15x 6l'
     head_size = calcsize(head_fmt)
-    (magic, format, ttisgmtcnt, ttisstdcnt,leapcnt, timecnt,
-        typecnt, charcnt) =  unpack(head_fmt, fp.read(head_size))
+    (magic, format, ttisgmtcnt, ttisstdcnt, leapcnt, timecnt,
+        typecnt, charcnt) = unpack(head_fmt, fp.read(head_size))
 
     # Make sure it is a tzfile(5) file
     assert magic == _byte_string('TZif'), 'Got magic %s' % repr(magic)
 
     # Read out the transition times, localtime indices and ttinfo structures.
     data_fmt = '>%(timecnt)dl %(timecnt)dB %(ttinfo)s %(charcnt)ds' % dict(
-        timecnt=timecnt, ttinfo='lBB'*typecnt, charcnt=charcnt)
+        timecnt=timecnt, ttinfo='lBB' * typecnt, charcnt=charcnt)
     data_size = calcsize(data_fmt)
     data = unpack(data_fmt, fp.read(data_size))
 
@@ -53,7 +51,7 @@ def build_tzinfo(zone, fp):
     i = 0
     while i < len(ttinfo_raw):
         # have we looked up this timezone name yet?
-        tzname_offset = ttinfo_raw[i+2]
+        tzname_offset = ttinfo_raw[i + 2]
         if tzname_offset not in tznames:
             nul = tznames_raw.find(_NULL, tzname_offset)
             if nul < 0:
@@ -61,12 +59,12 @@ def build_tzinfo(zone, fp):
             tznames[tzname_offset] = _std_string(
                 tznames_raw[tzname_offset:nul])
         ttinfo.append((ttinfo_raw[i],
-                       bool(ttinfo_raw[i+1]),
+                       bool(ttinfo_raw[i + 1]),
                        tznames[tzname_offset]))
         i += 3
 
     # Now build the timezone object
-    if len(transitions) == 0:
+    if len(ttinfo) == 1 or len(transitions) == 0:
         ttinfo[0][0], ttinfo[0][2]
         cls = type(zone, (StaticTzInfo,), dict(
             zone=zone,
@@ -91,21 +89,21 @@ def build_tzinfo(zone, fp):
             if not inf[1]:
                 dst = 0
             else:
-                for j in range(i-1, -1, -1):
+                for j in range(i - 1, -1, -1):
                     prev_inf = ttinfo[lindexes[j]]
                     if not prev_inf[1]:
                         break
-                dst = inf[0] - prev_inf[0] # dst offset
+                dst = inf[0] - prev_inf[0]  # dst offset
 
                 # Bad dst? Look further. DST > 24 hours happens when
                 # a timzone has moved across the international dateline.
-                if dst <= 0 or dst > 3600*3:
-                    for j in range(i+1, len(transitions)):
+                if dst <= 0 or dst > 3600 * 3:
+                    for j in range(i + 1, len(transitions)):
                         stdinf = ttinfo[lindexes[j]]
                         if not stdinf[1]:
                             dst = inf[0] - stdinf[0]
                             if dst > 0:
-                                break # Found a useful std time.
+                                break  # Found a useful std time.
 
             tzname = inf[2]
 
@@ -129,9 +127,7 @@ if __name__ == '__main__':
     from pprint import pprint
     base = os.path.join(os.path.dirname(__file__), 'zoneinfo')
     tz = build_tzinfo('Australia/Melbourne',
-                      open(os.path.join(base,'Australia','Melbourne'), 'rb'))
+                      open(os.path.join(base, 'Australia', 'Melbourne'), 'rb'))
     tz = build_tzinfo('US/Eastern',
-                      open(os.path.join(base,'US','Eastern'), 'rb'))
+                      open(os.path.join(base, 'US', 'Eastern'), 'rb'))
     pprint(tz._utc_transition_times)
-    #print tz.asPython(4)
-    #print tz.transitions_mapping

lib/pytz/tzinfo.py

@@ -13,6 +13,8 @@ from pytz.exceptions import AmbiguousTimeError, NonExistentTimeError
 __all__ = []
 
 _timedelta_cache = {}
+
+
 def memorized_timedelta(seconds):
     '''Create only one instance of each distinct timedelta'''
     try:
@@ -24,6 +26,8 @@ def memorized_timedelta(seconds):
 
 _epoch = datetime.utcfromtimestamp(0)
 _datetime_cache = {0: _epoch}
+
+
 def memorized_datetime(seconds):
     '''Create only one instance of each distinct datetime'''
     try:
@@ -36,21 +40,24 @@ def memorized_datetime(seconds):
         return dt
 
 _ttinfo_cache = {}
+
+
 def memorized_ttinfo(*args):
     '''Create only one instance of each distinct tuple'''
     try:
         return _ttinfo_cache[args]
     except KeyError:
         ttinfo = (
-                memorized_timedelta(args[0]),
-                memorized_timedelta(args[1]),
-                args[2]
-                )
+            memorized_timedelta(args[0]),
+            memorized_timedelta(args[1]),
+            args[2]
+        )
         _ttinfo_cache[args] = ttinfo
         return ttinfo
 
 _notime = memorized_timedelta(0)
 
+
 def _to_seconds(td):
     '''Convert a timedelta to seconds'''
     return td.seconds + td.days * 24 * 60 * 60
@@ -154,14 +161,20 @@ class DstTzInfo(BaseTzInfo):
     timezone definition.
     '''
     # Overridden in subclass
-    _utc_transition_times = None # Sorted list of DST transition times in UTC
-    _transition_info = None # [(utcoffset, dstoffset, tzname)] corresponding
-                            # to _utc_transition_times entries
+
+    # Sorted list of DST transition times, UTC
+    _utc_transition_times = None
+
+    # [(utcoffset, dstoffset, tzname)] corresponding to
+    # _utc_transition_times entries
+    _transition_info = None
+
     zone = None
 
     # Set in __init__
+
     _tzinfos = None
-    _dst = None # DST offset
+    _dst = None  # DST offset
 
     def __init__(self, _inf=None, _tzinfos=None):
         if _inf:
@@ -170,7 +183,8 @@ class DstTzInfo(BaseTzInfo):
         else:
             _tzinfos = {}
             self._tzinfos = _tzinfos
-            self._utcoffset, self._dst, self._tzname = self._transition_info[0]
+            self._utcoffset, self._dst, self._tzname = (
+                self._transition_info[0])
             _tzinfos[self._transition_info[0]] = self
             for inf in self._transition_info[1:]:
                 if inf not in _tzinfos:
@@ -178,8 +192,8 @@ class DstTzInfo(BaseTzInfo):
 
     def fromutc(self, dt):
         '''See datetime.tzinfo.fromutc'''
-        if (dt.tzinfo is not None
-            and getattr(dt.tzinfo, '_tzinfos', None) is not self._tzinfos):
+        if (dt.tzinfo is not None and
+                getattr(dt.tzinfo, '_tzinfos', None) is not self._tzinfos):
             raise ValueError('fromutc: dt.tzinfo is not self')
         dt = dt.replace(tzinfo=None)
         idx = max(0, bisect_right(self._utc_transition_times, dt) - 1)
@@ -337,8 +351,8 @@ class DstTzInfo(BaseTzInfo):
             # obtain the correct timezone by winding the clock back.
             else:
                 return self.localize(
-                    dt - timedelta(hours=6), is_dst=False) + timedelta(hours=6)
-
+                    dt - timedelta(hours=6),
+                    is_dst=False) + timedelta(hours=6)
 
         # If we get this far, we have multiple possible timezones - this
         # is an ambiguous case occuring during the end-of-DST transition.
@@ -351,9 +365,8 @@ class DstTzInfo(BaseTzInfo):
         # Filter out the possiblilities that don't match the requested
         # is_dst
         filtered_possible_loc_dt = [
-            p for p in possible_loc_dt
-                if bool(p.tzinfo._dst) == is_dst
-            ]
+            p for p in possible_loc_dt if bool(p.tzinfo._dst) == is_dst
+        ]
 
         # Hopefully we only have one possibility left. Return it.
         if len(filtered_possible_loc_dt) == 1:
@@ -372,9 +385,10 @@ class DstTzInfo(BaseTzInfo):
         # Choose the earliest (by UTC) applicable timezone if is_dst=True
         # Choose the latest (by UTC) applicable timezone if is_dst=False
         # i.e., behave like end-of-DST transition
-        dates = {} # utc -> local
+        dates = {}  # utc -> local
         for local_dt in filtered_possible_loc_dt:
-            utc_time = local_dt.replace(tzinfo=None) - local_dt.tzinfo._utcoffset
+            utc_time = (
+                local_dt.replace(tzinfo=None) - local_dt.tzinfo._utcoffset)
             assert utc_time not in dates
             dates[utc_time] = local_dt
         return dates[[min, max][not is_dst](dates)]
@@ -389,11 +403,11 @@ class DstTzInfo(BaseTzInfo):
         >>> tz = timezone('America/St_Johns')
         >>> ambiguous = datetime(2009, 10, 31, 23, 30)
 
-        >>> tz.utcoffset(ambiguous, is_dst=False)
-        datetime.timedelta(-1, 73800)
+        >>> str(tz.utcoffset(ambiguous, is_dst=False))
+        '-1 day, 20:30:00'
 
-        >>> tz.utcoffset(ambiguous, is_dst=True)
-        datetime.timedelta(-1, 77400)
+        >>> str(tz.utcoffset(ambiguous, is_dst=True))
+        '-1 day, 21:30:00'
 
         >>> try:
         ...     tz.utcoffset(ambiguous)
@@ -421,19 +435,19 @@ class DstTzInfo(BaseTzInfo):
 
         >>> normal = datetime(2009, 9, 1)
 
-        >>> tz.dst(normal)
-        datetime.timedelta(0, 3600)
-        >>> tz.dst(normal, is_dst=False)
-        datetime.timedelta(0, 3600)
-        >>> tz.dst(normal, is_dst=True)
-        datetime.timedelta(0, 3600)
+        >>> str(tz.dst(normal))
+        '1:00:00'
+        >>> str(tz.dst(normal, is_dst=False))
+        '1:00:00'
+        >>> str(tz.dst(normal, is_dst=True))
+        '1:00:00'
 
         >>> ambiguous = datetime(2009, 10, 31, 23, 30)
 
-        >>> tz.dst(ambiguous, is_dst=False)
-        datetime.timedelta(0)
-        >>> tz.dst(ambiguous, is_dst=True)
-        datetime.timedelta(0, 3600)
+        >>> str(tz.dst(ambiguous, is_dst=False))
+        '0:00:00'
+        >>> str(tz.dst(ambiguous, is_dst=True))
+        '1:00:00'
         >>> try:
         ...     tz.dst(ambiguous)
         ... except AmbiguousTimeError:
@@ -494,23 +508,22 @@ class DstTzInfo(BaseTzInfo):
             dst = 'STD'
         if self._utcoffset > _notime:
             return '<DstTzInfo %r %s+%s %s>' % (
-                    self.zone, self._tzname, self._utcoffset, dst
-                )
+                self.zone, self._tzname, self._utcoffset, dst
+            )
         else:
             return '<DstTzInfo %r %s%s %s>' % (
-                    self.zone, self._tzname, self._utcoffset, dst
-                )
+                self.zone, self._tzname, self._utcoffset, dst
+            )
 
     def __reduce__(self):
         # Special pickle to zone remains a singleton and to cope with
         # database changes.
         return pytz._p, (
-                self.zone,
-                _to_seconds(self._utcoffset),
-                _to_seconds(self._dst),
-                self._tzname
-                )
-
+            self.zone,
+            _to_seconds(self._utcoffset),
+            _to_seconds(self._dst),
+            self._tzname
+        )
 
 
 def unpickler(zone, utcoffset=None, dstoffset=None, tzname=None):
@@ -548,9 +561,9 @@ def unpickler(zone, utcoffset=None, dstoffset=None, tzname=None):
     # See if we can find an entry differing only by tzname. Abbreviations
     # get changed from the initial guess by the database maintainers to
     # match reality when this information is discovered.
-    for localized_tz in list(tz._tzinfos.values()):
-        if (localized_tz._utcoffset == utcoffset
-                and localized_tz._dst == dstoffset):
+    for localized_tz in tz._tzinfos.values():
+        if (localized_tz._utcoffset == utcoffset and
+                localized_tz._dst == dstoffset):
             return localized_tz
 
     # This (utcoffset, dstoffset) information has been removed from the