Your IP : 216.73.216.50
# -*- coding: utf-8 -*-
"""
This module offers timezone implementations subclassing the abstract
:py:class:`datetime.tzinfo` type. There are classes to handle tzfile format
files (usually are in :file:`/etc/localtime`, :file:`/usr/share/zoneinfo`,
etc), TZ environment string (in all known formats), given ranges (with help
from relative deltas), local machine timezone, fixed offset timezone, and UTC
timezone.
"""
import datetime
import struct
import time
import sys
import os
import bisect
import weakref
from collections import OrderedDict
import six
from six import string_types
from six.moves import _thread
from ._common import tzname_in_python2, _tzinfo
from ._common import tzrangebase, enfold
from ._common import _validate_fromutc_inputs
from ._factories import _TzSingleton, _TzOffsetFactory
from ._factories import _TzStrFactory
try:
from .win import tzwin, tzwinlocal
except ImportError:
tzwin = tzwinlocal = None
# For warning about rounding tzinfo
from warnings import warn
ZERO = datetime.timedelta(0)
EPOCH = datetime.datetime(1970, 1, 1, 0, 0)
EPOCHORDINAL = EPOCH.toordinal()
@six.add_metaclass(_TzSingleton)
class tzutc(datetime.tzinfo):
"""
This is a tzinfo object that represents the UTC time zone.
**Examples:**
.. doctest::
>>> from datetime import *
>>> from dateutil.tz import *
>>> datetime.now()
datetime.datetime(2003, 9, 27, 9, 40, 1, 521290)
>>> datetime.now(tzutc())
datetime.datetime(2003, 9, 27, 12, 40, 12, 156379, tzinfo=tzutc())
>>> datetime.now(tzutc()).tzname()
'UTC'
.. versionchanged:: 2.7.0
``tzutc()`` is now a singleton, so the result of ``tzutc()`` will
always return the same object.
.. doctest::
>>> from dateutil.tz import tzutc, UTC
>>> tzutc() is tzutc()
True
>>> tzutc() is UTC
True
"""
def utcoffset(self, dt):
return ZERO
def dst(self, dt):
return ZERO
@tzname_in_python2
def tzname(self, dt):
return "UTC"
def is_ambiguous(self, dt):
"""
Whether or not the "wall time" of a given datetime is ambiguous in this
zone.
:param dt:
A :py:class:`datetime.datetime`, naive or time zone aware.
:return:
Returns ``True`` if ambiguous, ``False`` otherwise.
.. versionadded:: 2.6.0
"""
return False
@_validate_fromutc_inputs
def fromutc(self, dt):
"""
Fast track version of fromutc() returns the original ``dt`` object for
any valid :py:class:`datetime.datetime` object.
"""
return dt
def __eq__(self, other):
if not isinstance(other, (tzutc, tzoffset)):
return NotImplemented
return (isinstance(other, tzutc) or
(isinstance(other, tzoffset) and other._offset == ZERO))
__hash__ = None
def __ne__(self, other):
return not (self == other)
def __repr__(self):
return "%s()" % self.__class__.__name__
__reduce__ = object.__reduce__
#: Convenience constant providing a :class:`tzutc()` instance
#:
#: .. versionadded:: 2.7.0
UTC = tzutc()
@six.add_metaclass(_TzOffsetFactory)
class tzoffset(datetime.tzinfo):
"""
A simple class for representing a fixed offset from UTC.
:param name:
The timezone name, to be returned when ``tzname()`` is called.
:param offset:
The time zone offset in seconds, or (since version 2.6.0, represented
as a :py:class:`datetime.timedelta` object).
"""
def __init__(self, name, offset):
self._name = name
try:
# Allow a timedelta
offset = offset.total_seconds()
except (TypeError, AttributeError):
pass
self._offset = datetime.timedelta(seconds=_get_supported_offset(offset))
def utcoffset(self, dt):
return self._offset
def dst(self, dt):
return ZERO
@tzname_in_python2
def tzname(self, dt):
return self._name
@_validate_fromutc_inputs
def fromutc(self, dt):
return dt + self._offset
def is_ambiguous(self, dt):
"""
Whether or not the "wall time" of a given datetime is ambiguous in this
zone.
:param dt:
A :py:class:`datetime.datetime`, naive or time zone aware.
:return:
Returns ``True`` if ambiguous, ``False`` otherwise.
.. versionadded:: 2.6.0
"""
return False
def __eq__(self, other):
if not isinstance(other, tzoffset):
return NotImplemented
return self._offset == other._offset
__hash__ = None
def __ne__(self, other):
return not (self == other)
def __repr__(self):
return "%s(%s, %s)" % (self.__class__.__name__,
repr(self._name),
int(self._offset.total_seconds()))
__reduce__ = object.__reduce__
class tzlocal(_tzinfo):
"""
A :class:`tzinfo` subclass built around the ``time`` timezone functions.
"""
def __init__(self):
super(tzlocal, self).__init__()
self._std_offset = datetime.timedelta(seconds=-time.timezone)
if time.daylight:
self._dst_offset = datetime.timedelta(seconds=-time.altzone)
else:
self._dst_offset = self._std_offset
self._dst_saved = self._dst_offset - self._std_offset
self._hasdst = bool(self._dst_saved)
self._tznames = tuple(time.tzname)
def utcoffset(self, dt):
if dt is None and self._hasdst:
return None
if self._isdst(dt):
return self._dst_offset
else:
return self._std_offset
def dst(self, dt):
if dt is None and self._hasdst:
return None
if self._isdst(dt):
return self._dst_offset - self._std_offset
else:
return ZERO
@tzname_in_python2
def tzname(self, dt):
return self._tznames[self._isdst(dt)]
def is_ambiguous(self, dt):
"""
Whether or not the "wall time" of a given datetime is ambiguous in this
zone.
:param dt:
A :py:class:`datetime.datetime`, naive or time zone aware.
:return:
Returns ``True`` if ambiguous, ``False`` otherwise.
.. versionadded:: 2.6.0
"""
naive_dst = self._naive_is_dst(dt)
return (not naive_dst and
(naive_dst != self._naive_is_dst(dt - self._dst_saved)))
def _naive_is_dst(self, dt):
timestamp = _datetime_to_timestamp(dt)
return time.localtime(timestamp + time.timezone).tm_isdst
def _isdst(self, dt, fold_naive=True):
# We can't use mktime here. It is unstable when deciding if
# the hour near to a change is DST or not.
#
# timestamp = time.mktime((dt.year, dt.month, dt.day, dt.hour,
# dt.minute, dt.second, dt.weekday(), 0, -1))
# return time.localtime(timestamp).tm_isdst
#
# The code above yields the following result:
#
# >>> import tz, datetime
# >>> t = tz.tzlocal()
# >>> datetime.datetime(2003,2,15,23,tzinfo=t).tzname()
# 'BRDT'
# >>> datetime.datetime(2003,2,16,0,tzinfo=t).tzname()
# 'BRST'
# >>> datetime.datetime(2003,2,15,23,tzinfo=t).tzname()
# 'BRST'
# >>> datetime.datetime(2003,2,15,22,tzinfo=t).tzname()
# 'BRDT'
# >>> datetime.datetime(2003,2,15,23,tzinfo=t).tzname()
# 'BRDT'
#
# Here is a more stable implementation:
#
if not self._hasdst:
return False
# Check for ambiguous times:
dstval = self._naive_is_dst(dt)
fold = getattr(dt, 'fold', None)
if self.is_ambiguous(dt):
if fold is not None:
return not self._fold(dt)
else:
return True
return dstval
def __eq__(self, other):
if isinstance(other, tzlocal):
return (self._std_offset == other._std_offset and
self._dst_offset == other._dst_offset)
elif isinstance(other, tzutc):
return (not self._hasdst and
self._tznames[0] in {'UTC', 'GMT'} and
self._std_offset == ZERO)
elif isinstance(other, tzoffset):
return (not self._hasdst and
self._tznames[0] == other._name and
self._std_offset == other._offset)
else:
return NotImplemented
__hash__ = None
def __ne__(self, other):
return not (self == other)
def __repr__(self):
return "%s()" % self.__class__.__name__
__reduce__ = object.__reduce__
class _ttinfo(object):
__slots__ = ["offset", "delta", "isdst", "abbr",
"isstd", "isgmt", "dstoffset"]
def __init__(self):
for attr in self.__slots__:
setattr(self, attr, None)
def __repr__(self):
l = []
for attr in self.__slots__:
value = getattr(self, attr)
if value is not None:
l.append("%s=%s" % (attr, repr(value)))
return "%s(%s)" % (self.__class__.__name__, ", ".join(l))
def __eq__(self, other):
if not isinstance(other, _ttinfo):
return NotImplemented
return (self.offset == other.offset and
self.delta == other.delta and
self.isdst == other.isdst and
self.abbr == other.abbr and
self.isstd == other.isstd and
self.isgmt == other.isgmt and
self.dstoffset == other.dstoffset)
__hash__ = None
def __ne__(self, other):
return not (self == other)
def __getstate__(self):
state = {}
for name in self.__slots__:
state[name] = getattr(self, name, None)
return state
def __setstate__(self, state):
for name in self.__slots__:
if name in state:
setattr(self, name, state[name])
class _tzfile(object):
"""
Lightweight class for holding the relevant transition and time zone
information read from binary tzfiles.
"""
attrs = ['trans_list', 'trans_list_utc', 'trans_idx', 'ttinfo_list',
'ttinfo_std', 'ttinfo_dst', 'ttinfo_before', 'ttinfo_first']
def __init__(self, **kwargs):
for attr in self.attrs:
setattr(self, attr, kwargs.get(attr, None))
class tzfile(_tzinfo):
"""
This is a ``tzinfo`` subclass that allows one to use the ``tzfile(5)``
format timezone files to extract current and historical zone information.
:param fileobj:
This can be an opened file stream or a file name that the time zone
information can be read from.
:param filename:
This is an optional parameter specifying the source of the time zone
information in the event that ``fileobj`` is a file object. If omitted
and ``fileobj`` is a file stream, this parameter will be set either to
``fileobj``'s ``name`` attribute or to ``repr(fileobj)``.
See `Sources for Time Zone and Daylight Saving Time Data
<https://data.iana.org/time-zones/tz-link.html>`_ for more information.
Time zone files can be compiled from the `IANA Time Zone database files
<https://www.iana.org/time-zones>`_ with the `zic time zone compiler
<https://www.freebsd.org/cgi/man.cgi?query=zic&sektion=8>`_
.. note::
Only construct a ``tzfile`` directly if you have a specific timezone
file on disk that you want to read into a Python ``tzinfo`` object.
If you want to get a ``tzfile`` representing a specific IANA zone,
(e.g. ``'America/New_York'``), you should call
:func:`dateutil.tz.gettz` with the zone identifier.
**Examples:**
Using the US Eastern time zone as an example, we can see that a ``tzfile``
provides time zone information for the standard Daylight Saving offsets:
.. testsetup:: tzfile
from dateutil.tz import gettz
from datetime import datetime
.. doctest:: tzfile
>>> NYC = gettz('America/New_York')
>>> NYC
tzfile('/usr/share/zoneinfo/America/New_York')
>>> print(datetime(2016, 1, 3, tzinfo=NYC)) # EST
2016-01-03 00:00:00-05:00
>>> print(datetime(2016, 7, 7, tzinfo=NYC)) # EDT
2016-07-07 00:00:00-04:00
The ``tzfile`` structure contains a fully history of the time zone,
so historical dates will also have the right offsets. For example, before
the adoption of the UTC standards, New York used local solar mean time:
.. doctest:: tzfile
>>> print(datetime(1901, 4, 12, tzinfo=NYC)) # LMT
1901-04-12 00:00:00-04:56
And during World War II, New York was on "Eastern War Time", which was a
state of permanent daylight saving time:
.. doctest:: tzfile
>>> print(datetime(1944, 2, 7, tzinfo=NYC)) # EWT
1944-02-07 00:00:00-04:00
"""
def __init__(self, fileobj, filename=None):
super(tzfile, self).__init__()
file_opened_here = False
if isinstance(fileobj, string_types):
self._filename = fileobj
fileobj = open(fileobj, 'rb')
file_opened_here = True
elif filename is not None:
self._filename = filename
elif hasattr(fileobj, "name"):
self._filename = fileobj.name
else:
self._filename = repr(fileobj)
if fileobj is not None:
if not file_opened_here:
fileobj = _nullcontext(fileobj)
with fileobj as file_stream:
tzobj = self._read_tzfile(file_stream)
self._set_tzdata(tzobj)
def _set_tzdata(self, tzobj):
""" Set the time zone data of this object from a _tzfile object """
# Copy the relevant attributes over as private attributes
for attr in _tzfile.attrs:
setattr(self, '_' + attr, getattr(tzobj, attr))
def _read_tzfile(self, fileobj):
out = _tzfile()
# From tzfile(5):
#
# The time zone information files used by tzset(3)
# begin with the magic characters "TZif" to identify
# them as time zone information files, followed by
# sixteen bytes reserved for future use, followed by
# six four-byte values of type long, written in a
# ``standard'' byte order (the high-order byte
# of the value is written first).
if fileobj.read(4).decode() != "TZif":
raise ValueError("magic not found")
fileobj.read(16)
(
# The number of UTC/local indicators stored in the file.
ttisgmtcnt,
# The number of standard/wall indicators stored in the file.
ttisstdcnt,
# The number of leap seconds for which data is
# stored in the file.
leapcnt,
# The number of "transition times" for which data
# is stored in the file.
timecnt,
# The number of "local time types" for which data
# is stored in the file (must not be zero).
typecnt,
# The number of characters of "time zone
# abbreviation strings" stored in the file.
charcnt,
) = struct.unpack(">6l", fileobj.read(24))
# The above header is followed by tzh_timecnt four-byte
# values of type long, sorted in ascending order.
# These values are written in ``standard'' byte order.
# Each is used as a transition time (as returned by
# time(2)) at which the rules for computing local time
# change.
if timecnt:
out.trans_list_utc = list(struct.unpack(">%dl" % timecnt,
fileobj.read(timecnt*4)))
else:
out.trans_list_utc = []
# Next come tzh_timecnt one-byte values of type unsigned
# char; each one tells which of the different types of
# ``local time'' types described in