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# This code was originally contributed by Jeffrey Harris.
import datetime
import struct
import _winreg
__author__ = "Jeffrey Harris & Gustavo Niemeyer <gustavo@niemeyer.net>"
__all__ = ["tzwin", "tzwinlocal"]
ONEWEEK = datetime.timedelta(7)
TZKEYNAMENT = r"SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones"
TZKEYNAME9X = r"SOFTWARE\Microsoft\Windows\CurrentVersion\Time Zones"
TZLOCALKEYNAME = r"SYSTEM\CurrentControlSet\Control\TimeZoneInformation"
def _settzkeyname():
global TZKEYNAME
handle = _winreg.ConnectRegistry(None, _winreg.HKEY_LOCAL_MACHINE)
try:
_winreg.OpenKey(handle, TZKEYNAMENT).Close()
TZKEYNAME = TZKEYNAMENT
except WindowsError:
TZKEYNAME = TZKEYNAME9X
handle.Close()
_settzkeyname()
class tzwinbase(datetime.tzinfo):
"""tzinfo class based on win32's timezones available in the registry."""
def utcoffset(self, dt):
if self._isdst(dt):
return datetime.timedelta(minutes=self._dstoffset)
else:
return datetime.timedelta(minutes=self._stdoffset)
def dst(self, dt):
if self._isdst(dt):
minutes = self._dstoffset - self._stdoffset
return datetime.timedelta(minutes=minutes)
else:
return datetime.timedelta(0)
def tzname(self, dt):
if self._isdst(dt):
return self._dstname
else:
return self._stdname
def list():
"""Return a list of all time zones known to the system."""
handle = _winreg.ConnectRegistry(None, _winreg.HKEY_LOCAL_MACHINE)
tzkey = _winreg.OpenKey(handle, TZKEYNAME)
result = [_winreg.EnumKey(tzkey, i)
for i in range(_winreg.QueryInfoKey(tzkey)[0])]
tzkey.Close()
handle.Close()
return result
list = staticmethod(list)
def display(self):
return self._display
def _isdst(self, dt):
dston = picknthweekday(dt.year, self._dstmonth, self._dstdayofweek,
self._dsthour, self._dstminute,
self._dstweeknumber)
dstoff = picknthweekday(dt.year, self._stdmonth, self._stddayofweek,
self._stdhour, self._stdminute,
self._stdweeknumber)
if dston < dstoff:
return dston <= dt.replace(tzinfo=None) < dstoff
else:
return not dstoff <= dt.replace(tzinfo=None) < dston
class tzwin(tzwinbase):
def __init__(self, name):
self._name = name
handle = _winreg.ConnectRegistry(None, _winreg.HKEY_LOCAL_MACHINE)
tzkey = _winreg.OpenKey(handle, "%s\%s" % (TZKEYNAME, name))
keydict = valuestodict(tzkey)
tzkey.Close()
handle.Close()
self._stdname = keydict["Std"].encode("iso-8859-1")
self._dstname = keydict["Dlt"].encode("iso-8859-1")
self._display = keydict["Display"]
# See http://ww_winreg.jsiinc.com/SUBA/tip0300/rh0398.htm
tup = struct.unpack("=3l16h", keydict["TZI"])
self._stdoffset = -tup[0]-tup[1] # Bias + StandardBias * -1
self._dstoffset = self._stdoffset-tup[2] # + DaylightBias * -1
(self._stdmonth,
self._stddayofweek, # Sunday = 0
self._stdweeknumber, # Last = 5
self._stdhour,
self._stdminute) = tup[4:9]
(self._dstmonth,
self._dstdayofweek, # Sunday = 0
self._dstweeknumber, # Last = 5
self._dsthour,
self._dstminute) = tup[12:17]
def __repr__(self):
return "tzwin(%s)" % repr(self._name)
def __reduce__(self):
return (self.__class__, (self._name,))
class tzwinlocal(tzwinbase):
def __init__(self):
handle = _winreg.ConnectRegistry(None, _winreg.HKEY_LOCAL_MACHINE)
tzlocalkey = _winreg.OpenKey(handle, TZLOCALKEYNAME)
keydict = valuestodict(tzlocalkey)
tzlocalkey.Close()
self._stdname = keydict["StandardName"].encode("iso-8859-1")
self._dstname = keydict["DaylightName"].encode("iso-8859-1")
try:
tzkey = _winreg.OpenKey(handle, "%s\%s"%(TZKEYNAME, self._stdname))
_keydict = valuestodict(tzkey)
self._display = _keydict["Display"]
tzkey.Close()
except OSError:
self._display = None
handle.Close()
self._stdoffset = -keydict["Bias"]-keydict["StandardBias"]
self._dstoffset = self._stdoffset-keydict["DaylightBias"]
# See http://ww_winreg.jsiinc.com/SUBA/tip0300/rh0398.htm
tup = struct.unpack("=8h", keydict["StandardStart"])
(self._stdmonth,
self._stddayofweek, # Sunday = 0
self._stdweeknumber, # Last = 5
self._stdhour,
self._stdminute) = tup[1:6]
tup = struct.unpack("=8h", keydict["DaylightStart"])
(self._dstmonth,
self._dstdayofweek, # Sunday = 0
self._dstweeknumber, # Last = 5
self._dsthour,
self._dstminute) = tup[1:6]
def __reduce__(self):
return (self.__class__, ())
def picknthweekday(year, month, dayofweek, hour, minute, whichweek):
"""dayofweek == 0 means Sunday, whichweek 5 means last instance"""
first = datetime.datetime(year, month, 1, hour, minute)
weekdayone = first.replace(day=((dayofweek-first.isoweekday())%7+1))
for n in xrange(whichweek):
dt = weekdayone+(whichweek-n)*ONEWEEK
if dt.month == month:
return dt
def valuestodict(key):
"""Convert a registry key's values to a dictionary."""
dict = {}
size = _winreg.QueryInfoKey(key)[1]
for i in range(size):
data = _winreg.EnumValue(key, i)
dict[data[0]] = data[1]
return dict
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