Viewing file:  tz.py (33.07 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
# -*- coding: utf-8 -*-
"""
This module offers timezone implementations subclassing the abstract
:py:`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
from six import string_types, PY3
from ._common import tzname_in_python2
try:
from .win import tzwin, tzwinlocal
except ImportError:
tzwin = tzwinlocal = None
relativedelta = None
parser = None
rrule = None
ZERO = datetime.timedelta(0)
EPOCHORDINAL = datetime.datetime.utcfromtimestamp(0).toordinal()
class tzutc(datetime.tzinfo):
def utcoffset(self, dt):
return ZERO
def dst(self, dt):
return ZERO
@tzname_in_python2
def tzname(self, dt):
return "UTC"
def __eq__(self, other):
return (isinstance(other, tzutc) or
(isinstance(other, tzoffset) and other._offset == ZERO))
def __ne__(self, other):
return not self.__eq__(other)
def __repr__(self):
return "%s()" % self.__class__.__name__
__reduce__ = object.__reduce__
class tzoffset(datetime.tzinfo):
def __init__(self, name, offset):
self._name = name
self._offset = datetime.timedelta(seconds=offset)
def utcoffset(self, dt):
return self._offset
def dst(self, dt):
return ZERO
@tzname_in_python2
def tzname(self, dt):
return self._name
def __eq__(self, other):
return (isinstance(other, tzoffset) and
self._offset == other._offset)
def __ne__(self, other):
return not self.__eq__(other)
def __repr__(self):
return "%s(%s, %s)" % (self.__class__.__name__,
repr(self._name),
self._offset.days*86400+self._offset.seconds)
__reduce__ = object.__reduce__
class tzlocal(datetime.tzinfo):
def __init__(self):
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
def utcoffset(self, dt):
if dt is None:
return dt
if self._isdst(dt):
return self._dst_offset
else:
return self._std_offset
def dst(self, dt):
if self._isdst(dt):
return self._dst_offset-self._std_offset
else:
return ZERO
@tzname_in_python2
def tzname(self, dt):
return time.tzname[self._isdst(dt)]
def _isdst(self, dt):
# 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:
#
timestamp = ((dt.toordinal() - EPOCHORDINAL) * 86400
+ dt.hour * 3600
+ dt.minute * 60
+ dt.second)
return time.localtime(timestamp+time.timezone).tm_isdst
def __eq__(self, other):
return (isinstance(other, tzlocal) and
(self._std_offset == other._std_offset and
self._dst_offset == other._dst_offset))
def __ne__(self, other):
return not self.__eq__(other)
def __repr__(self):
return "%s()" % self.__class__.__name__
__reduce__ = object.__reduce__
class _ttinfo(object):
__slots__ = ["offset", "delta", "isdst", "abbr", "isstd", "isgmt"]
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 False
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)
def __ne__(self, other):
return not self.__eq__(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(datetime.tzinfo):
# http://www.twinsun.com/tz/tz-link.htm
# ftp://ftp.iana.org/tz/tz*.tar.gz
def __init__(self, fileobj, filename=None):
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)
# 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).
try:
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:
self._trans_list = struct.unpack(">%dl" % timecnt,
fileobj.read(timecnt*4))
else:
self._trans_list = []
# 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 the file is associated
# with the same-indexed transition time. These values
# serve as indices into an array of ttinfo structures that
# appears next in the file.
if timecnt:
self._trans_idx = struct.unpack(">%dB" % timecnt,
fileobj.read(timecnt))
else:
self._trans_idx = []
# Each ttinfo structure is written as a four-byte value
# for tt_gmtoff of type long, in a standard byte
# order, followed by a one-byte value for tt_isdst
# and a one-byte value for tt_abbrind. In each
# structure, tt_gmtoff gives the number of
# seconds to be added to UTC, tt_isdst tells whether
# tm_isdst should be set by localtime(3), and
# tt_abbrind serves as an index into the array of
# time zone abbreviation characters that follow the
# ttinfo structure(s) in the file.
ttinfo = []
for i in range(typecnt):
ttinfo.append(struct.unpack(">lbb", fileobj.read(6)))
abbr = fileobj.read(charcnt).decode()
# Then there are tzh_leapcnt pairs of four-byte
# values, written in standard byte order; the
# first value of each pair gives the time (as
# returned by time(2)) at which a leap second
# occurs; the second gives the total number of
# leap seconds to be applied after the given time.
# The pairs of values are sorted in ascending order
# by time.
# Not used, for now (but read anyway for correct file position)
if leapcnt:
leap = struct.unpack(">%dl" % (leapcnt*2),
fileobj.read(leapcnt*8))
# Then there are tzh_ttisstdcnt standard/wall
# indicators, each stored as a one-byte value;
# they tell whether the transition times associated
# with local time types were specified as standard
# time or wall clock time, and are used when
# a time zone file is used in handling POSIX-style
# time zone environment variables.
if ttisstdcnt:
isstd = struct.unpack(">%db" % ttisstdcnt,
fileobj.read(ttisstdcnt))
# Finally, there are tzh_ttisgmtcnt UTC/local
# indicators, each stored as a one-byte value;
# they tell whether the transition times associated
# with local time types were specified as UTC or
# local time, and are used when a time zone file
# is used in handling POSIX-style time zone envi-
# ronment variables.
if ttisgmtcnt:
isgmt = struct.unpack(">%db" % ttisgmtcnt,
fileobj.read(ttisgmtcnt))
# ** Everything has been read **
finally:
if file_opened_here:
fileobj.close()
# Build ttinfo list
self._ttinfo_list = []
for i in range(typecnt):
gmtoff, isdst, abbrind = ttinfo[i]
# Round to full-minutes if that's not the case. Python's
# datetime doesn't accept sub-minute timezones. Check
# http://python.org/sf/1447945 for some information.
gmtoff = (gmtoff+30)//60*60
tti = _ttinfo()
tti.offset = gmtoff
tti.delta = datetime.timedelta(seconds=gmtoff)
tti.isdst = isdst
tti.abbr = abbr[abbrind:abbr.find('\x00', abbrind)]
tti.isstd = (ttisstdcnt > i and isstd[i] != 0)
tti.isgmt = (ttisgmtcnt > i and isgmt[i] != 0)
self._ttinfo_list.append(tti)
# Replace ttinfo indexes for ttinfo objects.
trans_idx = []
for idx in self._trans_idx:
trans_idx.append(self._ttinfo_list[idx])
self._trans_idx = tuple(trans_idx)
# Set standard, dst, and before ttinfos. before will be
# used when a given time is before any transitions,
# and will be set to the first non-dst ttinfo, or to
# the first dst, if all of them are dst.
self._ttinfo_std = None
self._ttinfo_dst = None
self._ttinfo_before = None
if self._ttinfo_list:
if not self._trans_list:
self._ttinfo_std = self._ttinfo_first = self._ttinfo_list[0]
else:
for i in range(timecnt-1, -1, -1):
tti = self._trans_idx[i]
if not self._ttinfo_std and not tti.isdst:
self._ttinfo_std = tti
elif not self._ttinfo_dst and tti.isdst:
self._ttinfo_dst = tti
if self._ttinfo_std and self._ttinfo_dst:
break
else:
if self._ttinfo_dst and not self._ttinfo_std:
self._ttinfo_std = self._ttinfo_dst
for tti in self._ttinfo_list:
if not tti.isdst:
self._ttinfo_before = tti
break
else:
self._ttinfo_before = self._ttinfo_list[0]
# Now fix transition times to become relative to wall time.
#
# I'm not sure about this. In my tests, the tz source file
# is setup to wall time, and in the binary file isstd and
# isgmt are off, so it should be in wall time. OTOH, it's
# always in gmt time. Let me know if you have comments
# about this.
laststdoffset = 0
self._trans_list = list(self._trans_list)
for i in range(len(self._trans_list)):
tti = self._trans_idx[i]
if not tti.isdst:
# This is std time.
self._trans_list[i] += tti.offset
laststdoffset = tti.offset
else:
# This is dst time. Convert to std.
self._trans_list[i] += laststdoffset
self._trans_list = tuple(self._trans_list)
def _find_ttinfo(self, dt, laststd=0):
timestamp = ((dt.toordinal() - EPOCHORDINAL) * 86400
+ dt.hour * 3600
+ dt.minute * 60
+ dt.second)
idx = 0
for trans in self._trans_list:
if timestamp < trans:
break
idx += 1
else:
return self._ttinfo_std
if idx == 0:
return self._ttinfo_before
if laststd:
while idx > 0:
tti = self._trans_idx[idx-1]
if not tti.isdst:
return tti
idx -= 1
else:
return self._ttinfo_std
else:
return self._trans_idx[idx-1]
def utcoffset(self, dt):
if dt is None:
return None
if not self._ttinfo_std:
return ZERO
return self._find_ttinfo(dt).delta
def dst(self, dt):
if not self._ttinfo_dst:
return ZERO
tti = self._find_ttinfo(dt)
if not tti.isdst:
return ZERO
# The documentation says that utcoffset()-dst() must
# be constant for every dt.
return tti.delta-self._find_ttinfo(dt, laststd=1).delta
# An alternative for that would be:
#
# return self._ttinfo_dst.offset-self._ttinfo_std.offset
#
# However, this class stores historical changes in the
# dst offset, so I belive that this wouldn't be the right
# way to implement this.
@tzname_in_python2
def tzname(self, dt):
if not self._ttinfo_std:
return None
return self._find_ttinfo(dt).abbr
def __eq__(self, other):
if not isinstance(other, tzfile):
return False
return (self._trans_list == other._trans_list and
self._trans_idx == other._trans_idx and
self._ttinfo_list == other._ttinfo_list)
def __ne__(self, other):
return not self.__eq__(other)
def __repr__(self):
return "%s(%s)" % (self.__class__.__name__, repr(self._filename))
def __reduce__(self):
if not os.path.isfile(self._filename):
raise ValueError("Unpickable %s class" % self.__class__.__name__)
return (self.__class__, (self._filename,))
class tzrange(datetime.tzinfo):
def __init__(self, stdabbr, stdoffset=None,
dstabbr=None, dstoffset=None,
start=None, end=None):
global relativedelta
if not relativedelta:
from dateutil import relativedelta
self._std_abbr = stdabbr
self._dst_abbr = dstabbr
if stdoffset is not None:
self._std_offset = datetime.timedelta(seconds=stdoffset)
else:
self._std_offset = ZERO
if dstoffset is not None:
self._dst_offset = datetime.timedelta(seconds=dstoffset)
elif dstabbr and stdoffset is not None:
self._dst_offset = self._std_offset+datetime.timedelta(hours=+1)
else:
self._dst_offset = ZERO
if dstabbr and start is None:
self._start_delta = relativedelta.relativedelta(
hours=+2, month=4, day=1, weekday=relativedelta.SU(+1))
else:
self._start_delta = start
if dstabbr and end is None:
self._end_delta = relativedelta.relativedelta(
hours=+1, month=10, day=31, weekday=relativedelta.SU(-1))
else:
self._end_delta = end
def utcoffset(self, dt):
if dt is None:
return None
if self._isdst(dt):
return self._dst_offset
else:
return self._std_offset
def dst(self, dt):
if self._isdst(dt):
return self._dst_offset-self._std_offset
else:
return ZERO
@tzname_in_python2
def tzname(self, dt):
if self._isdst(dt):
return self._dst_abbr
else:
return self._std_abbr
def _isdst(self, dt):
if not self._start_delta:
return False
year = datetime.datetime(dt.year, 1, 1)
start = year+self._start_delta
end = year+self._end_delta
dt = dt.replace(tzinfo=None)
if start < end:
return dt >= start and dt < end
else:
return dt >= start or dt < end
def __eq__(self, other):
if not isinstance(other, tzrange):
return False
return (self._std_abbr == other._std_abbr and
self._dst_abbr == other._dst_abbr and
self._std_offset == other._std_offset and
self._dst_offset == other._dst_offset and
self._start_delta == other._start_delta and
self._end_delta == other._end_delta)
def __ne__(self, other):
return not self.__eq__(other)
def __repr__(self):
return "%s(...)" % self.__class__.__name__
__reduce__ = object.__reduce__
class tzstr(tzrange):
def __init__(self, s):
global parser
if not parser:
from dateutil import parser
self._s = s
res = parser._parsetz(s)
if res is None:
raise ValueError("unknown string format")
# Here we break the compatibility with the TZ variable handling.
# GMT-3 actually *means* the timezone -3.
if res.stdabbr in ("GMT", "UTC"):
res.stdoffset *= -1
# We must initialize it first, since _delta() needs
# _std_offset and _dst_offset set. Use False in start/end
# to avoid building it two times.
tzrange.__init__(self, res.stdabbr, res.stdoffset,
res.dstabbr, res.dstoffset,
start=False, end=False)
if not res.dstabbr:
self._start_delta = None
self._end_delta = None
else:
self._start_delta = self._delta(res.start)
if self._start_delta:
self._end_delta = self._delta(res.end, isend=1)
def _delta(self, x, isend=0):
kwargs = {}
if x.month is not None:
kwargs["month"] = x.month
if x.weekday is not None:
kwargs["weekday"] = relativedelta.weekday(x.weekday, x.week)
if x.week > 0:
kwargs["day"] = 1
else:
kwargs["day"] = 31
elif x.day:
kwargs["day"] = x.day
elif x.yday is not None:
kwargs["yearday"] = x.yday
elif x.jyday is not None:
kwargs["nlyearday"] = x.jyday
if not kwargs:
# Default is to start on first sunday of april, and end
# on last sunday of october.
if not isend:
kwargs["month"] = 4
kwargs["day"] = 1
kwargs["weekday"] = relativedelta.SU(+1)
else:
kwargs["month"] = 10
kwargs["day"] = 31
kwargs["weekday"] = relativedelta.SU(-1)
if x.time is not None:
kwargs["seconds"] = x.time
else:
# Default is 2AM.
kwargs["seconds"] = 7200
if isend:
# Convert to standard time, to follow the documented way
# of working with the extra hour. See the documentation
# of the tzinfo class.
delta = self._dst_offset-self._std_offset
kwargs["seconds"] -= delta.seconds+delta.days*86400
return relativedelta.relativedelta(**kwargs)
def __repr__(self):
return "%s(%s)" % (self.__class__.__name__, repr(self._s))
class _tzicalvtzcomp(object):
def __init__(self, tzoffsetfrom, tzoffsetto, isdst,
tzname=None, rrule=None):
self.tzoffsetfrom = datetime.timedelta(seconds=tzoffsetfrom)
self.tzoffsetto = datetime.timedelta(seconds=tzoffsetto)
self.tzoffsetdiff = self.tzoffsetto-self.tzoffsetfrom
self.isdst = isdst
self.tzname = tzname
self.rrule = rrule
class _tzicalvtz(datetime.tzinfo):
def __init__(self, tzid, comps=[]):
self._tzid = tzid
self._comps = comps
self._cachedate = []
self._cachecomp = []
def _find_comp(self, dt):
if len(self._comps) == 1:
return self._comps[0]
dt = dt.replace(tzinfo=None)
try:
return self._cachecomp[self._cachedate.index(dt)]
except ValueError:
pass
lastcomp = None
lastcompdt = None
for comp in self._comps:
if not comp.isdst:
# Handle the extra hour in DST -> STD
compdt = comp.rrule.before(dt-comp.tzoffsetdiff, inc=True)
else:
compdt = comp.rrule.before(dt, inc=True)
if compdt and (not lastcompdt or lastcompdt < compdt):
lastcompdt = compdt
lastcomp = comp
if not lastcomp:
# RFC says nothing about what to do when a given
# time is before the first onset date. We'll look for the
# first standard component, or the first component, if
# none is found.
for comp in self._comps:
if not comp.isdst:
lastcomp = comp
break
else:
lastcomp = comp[0]
self._cachedate.insert(0, dt)
self._cachecomp.insert(0, lastcomp)
if len(self._cachedate) > 10:
self._cachedate.pop()
self._cachecomp.pop()
return lastcomp
def utcoffset(self, dt):
if dt is None:
return None
return self._find_comp(dt).tzoffsetto
def dst(self, dt):
comp = self._find_comp(dt)
if comp.isdst:
return comp.tzoffsetdiff
else:
return ZERO
@tzname_in_python2
def tzname(self, dt):
return self._find_comp(dt).tzname
def __repr__(self):
return "<tzicalvtz %s>" % repr(self._tzid)
__reduce__ = object.__reduce__
class tzical(object):
def __init__(self, fileobj):
global rrule
if not rrule:
from dateutil import rrule
if isinstance(fileobj, string_types):
self._s = fileobj
# ical should be encoded in UTF-8 with CRLF
fileobj = open(fileobj, 'r')
elif hasattr(fileobj, "name"):
self._s = fileobj.name
else:
self._s = repr(fileobj)
self._vtz = {}
self._parse_rfc(fileobj.read())
def keys(self):
return list(self._vtz.keys())
def get(self, tzid=None):
if tzid is None:
keys = list(self._vtz.keys())
if len(keys) == 0:
raise ValueError("no timezones defined")
elif len(keys) > 1:
raise ValueError("more than one timezone available")
tzid = keys[0]
return self._vtz.get(tzid)
def _parse_offset(self, s):
s = s.strip()
if not s:
raise ValueError("empty offset")
if s[0] in ('+', '-'):
signal = (-1, +1)[s[0] == '+']
s = s[1:]
else:
signal = +1
if len(s) == 4:
return (int(s[:2])*3600+int(s[2:])*60)*signal
elif len(s) == 6:
return (int(s[:2])*3600+int(s[2:4])*60+int(s[4:]))*signal
else:
raise ValueError("invalid offset: "+s)
def _parse_rfc(self, s):
lines = s.splitlines()
if not lines:
raise ValueError("empty string")
# Unfold
i = 0
while i < len(lines):
line = lines[i].rstrip()
if not line:
del lines[i]
elif i > 0 and line[0] == " ":
lines[i-1] += line[1:]
del lines[i]
else:
i += 1
tzid = None
comps = []
invtz = False
comptype = None
for line in lines:
if not line:
continue
name, value = line.split(':', 1)
parms = name.split(';')
if not parms:
raise ValueError("empty property name")
name = parms[0].upper()
parms = parms[1:]
if invtz:
if name == "BEGIN":
if value in ("STANDARD", "DAYLIGHT"):
# Process component
pass
else:
raise ValueError("unknown component: "+value)
comptype = value
founddtstart = False
tzoffsetfrom = None
tzoffsetto = None
rrulelines = []
tzname = None
elif name == "END":
if value == "VTIMEZONE":
if comptype:
raise ValueError("component not closed: "+comptype)
if not tzid:
raise ValueError("mandatory TZID not found")
if not comps:
raise ValueError(
"at least one component is needed")
# Process vtimezone
self._vtz[tzid] = _tzicalvtz(tzid, comps)
invtz = False
elif value == comptype:
if not founddtstart:
raise ValueError("mandatory DTSTART not found")
if tzoffsetfrom is None:
raise ValueError(
"mandatory TZOFFSETFROM not found")
if tzoffsetto is None:
raise ValueError(
"mandatory TZOFFSETFROM not found")
# Process component
rr = None
if rrulelines:
rr = rrule.rrulestr("\n".join(rrulelines),
compatible=True,
ignoretz=True,
cache=True)
comp = _tzicalvtzcomp(tzoffsetfrom, tzoffsetto,
(comptype == "DAYLIGHT"),
tzname, rr)
comps.append(comp)
comptype = None
else:
raise ValueError("invalid component end: "+value)
elif comptype:
if name == "DTSTART":
rrulelines.append(line)
founddtstart = True
elif name in ("RRULE", "RDATE", "EXRULE", "EXDATE"):
rrulelines.append(line)
elif name == "TZOFFSETFROM":
if parms:
raise ValueError(
"unsupported %s parm: %s " % (name, parms[0]))
tzoffsetfrom = self._parse_offset(value)
elif name == "TZOFFSETTO":
if parms:
raise ValueError(
"unsupported TZOFFSETTO parm: "+parms[0])
tzoffsetto = self._parse_offset(value)
elif name == "TZNAME":
if parms:
raise ValueError(
"unsupported TZNAME parm: "+parms[0])
tzname = value
elif name == "COMMENT":
pass
else:
raise ValueError("unsupported property: "+name)
else:
if name == "TZID":
if parms:
raise ValueError(
"unsupported TZID parm: "+parms[0])
tzid = value
elif name in ("TZURL", "LAST-MODIFIED", "COMMENT"):
pass
else:
raise ValueError("unsupported property: "+name)
elif name == "BEGIN" and value == "VTIMEZONE":
tzid = None
comps = []
invtz = True
def __repr__(self):
return "%s(%s)" % (self.__class__.__name__, repr(self._s))
if sys.platform != "win32":
TZFILES = ["/etc/localtime", "localtime"]
TZPATHS = ["/usr/share/zoneinfo", "/usr/lib/zoneinfo", "/etc/zoneinfo"]
else:
TZFILES = []
TZPATHS = []
def gettz(name=None):
tz = None
if not name:
try:
name = os.environ["TZ"]
except KeyError:
pass
if name is None or name == ":":
for filepath in TZFILES:
if not os.path.isabs(filepath):
filename = filepath
for path in TZPATHS:
filepath = os.path.join(path, filename)
if os.path.isfile(filepath):
break
else:
continue
if os.path.isfile(filepath):
try:
tz = tzfile(filepath)
break
except (IOError, OSError, ValueError):
pass
else:
tz = tzlocal()
else:
if name.startswith(":"):
name = name[:-1]
if os.path.isabs(name):
if os.path.isfile(name):
tz = tzfile(name)
else:
tz = None
else:
for path in TZPATHS:
filepath = os.path.join(path, name)
if not os.path.isfile(filepath):
filepath = filepath.replace(' ', '_')
if not os.path.isfile(filepath):
continue
try:
tz = tzfile(filepath)
break
except (IOError, OSError, ValueError):
pass
else:
tz = None
if tzwin is not None:
try:
tz = tzwin(name)
except WindowsError:
tz = None
if not tz:
from dateutil.zoneinfo import gettz
tz = gettz(name)
if not tz:
for c in name:
# name must have at least one offset to be a tzstr
if c in "0123456789":
try:
tz = tzstr(name)
except ValueError:
pass
break
else:
if name in ("GMT", "UTC"):
tz = tzutc()
elif name in time.tzname:
tz = tzlocal()
return tz
# vim:ts=4:sw=4:et
|