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- Metadata-Version: 2.0
- Name: pytz
- Version: 2018.7
- Summary: World timezone definitions, modern and historical
- Home-page: http://pythonhosted.org/pytz
- Author: Stuart Bishop
- Author-email: stuart@stuartbishop.net
- Maintainer: Stuart Bishop
- Maintainer-email: stuart@stuartbishop.net
- License: MIT
- Download-URL: https://pypi.org/project/pytz/
- Keywords: timezone,tzinfo,datetime,olson,time
- Platform: Independent
- Classifier: Development Status :: 6 - Mature
- Classifier: Intended Audience :: Developers
- Classifier: License :: OSI Approved :: MIT License
- Classifier: Natural Language :: English
- Classifier: Operating System :: OS Independent
- Classifier: Programming Language :: Python
- Classifier: Programming Language :: Python :: 2
- Classifier: Programming Language :: Python :: 2.4
- Classifier: Programming Language :: Python :: 2.5
- Classifier: Programming Language :: Python :: 2.6
- Classifier: Programming Language :: Python :: 2.7
- Classifier: Programming Language :: Python :: 3
- Classifier: Programming Language :: Python :: 3.0
- Classifier: Programming Language :: Python :: 3.1
- Classifier: Programming Language :: Python :: 3.2
- Classifier: Programming Language :: Python :: 3.3
- Classifier: Programming Language :: Python :: 3.4
- Classifier: Programming Language :: Python :: 3.5
- Classifier: Programming Language :: Python :: 3.6
- Classifier: Topic :: Software Development :: Libraries :: Python Modules
-
- 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) # /!\ Does not work this way!
- '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) # /!\ Not recommended except for UTC
- '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 is more easily done, using the
- standard astimezone method.
-
- >>> 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 = 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'
- >>> utc_dt == utc_dt2
- True
-
- 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 resolve 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
- >>> 'Australia/Yancowinna' in all_timezones
- True
- >>> 'Australia/Yancowinna' 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
-
-
- Internationalization - i18n/l10n
- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
- Pytz is an interface to the IANA database, which uses ASCII names. The `Unicode Consortium's Unicode Locales (CLDR) <http://cldr.unicode.org>`_
- project provides translations. Thomas Khyn's
- `l18n <https://pypi.org/project/l18n/>`_ package can be used to access
- these translations from Python.
-
-
- 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 <https://pypi.org/project/pytz/>`_. The code that is used
- to generate this distribution is hosted on launchpad.net and available
- using git::
-
- git clone https://git.launchpad.net/pytz
-
- A mirror on github is also available at https://github.com/stub42/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>
-
-
-
-
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