Extendsstampa corretta di tempo che utilizzano fusi orari, Python
Ok, non stanno avendo una buona giornata di oggi.
Quando si collega l'oggetto tzinfo corretto a un'istanza datetime, e quindi lo si strftime() esso, ANCORA esce in UTC, apparentemente ignorando il bellissimo oggetto tzinfo ad esso collegato.
# python 2.5.4 now = datetime.now() print now.strftime("%a %b %d %X") # %X is "locale's appropriate time rep" pst = now.replace(tzinfo=Pacific) print pst.strftime("%a %b %d %X")
otteniamo:
Mon Jan 18 17:30:16 Mon Jan 18 17:30:16
ho trovato se aggiungo% z, posso aggiungere la differenza sua presunta di aver calcolato:
Mon Jan 18 17:32:38 Mon Jan 18 17:32:38 -0800
It pochi chiodini sul -8 lì, come per dire "fai tu stesso, foo".
Ma voglio che strftime() mi dia semplicemente una stringa CON TEMPO LOCALE PRECOMPUTATO.
Come posso ottenere strftime() per fare la matematica di sottrazione dell'ora per me quando lo strftime()?
Il codice completo che sto utilizzando è di seguito.
from datetime import tzinfo, timedelta, datetime
ZERO = timedelta(0)
HOUR = timedelta(hours=1)
# A UTC class.
class UTC(tzinfo):
"""UTC"""
def utcoffset(self, dt):
return ZERO
def tzname(self, dt):
return "UTC"
def dst(self, dt):
return ZERO
utc = 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.__name = name
def utcoffset(self, dt):
return self.__offset
def tzname(self, dt):
return self.__name
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)
if _time.daylight:
DSTOFFSET = timedelta(seconds = -_time.altzone)
else:
DSTOFFSET = STDOFFSET
DSTDIFF = DSTOFFSET - STDOFFSET
class LocalTimezone(tzinfo):
def utcoffset(self, dt):
if self._isdst(dt):
return DSTOFFSET
else:
return STDOFFSET
def dst(self, dt):
if self._isdst(dt):
return DSTDIFF
else:
return ZERO
def tzname(self, dt):
return _time.tzname[self._isdst(dt)]
def _isdst(self, dt):
tt = (dt.year, dt.month, dt.day,
dt.hour, dt.minute, dt.second,
dt.weekday(), 0, -1)
stamp = _time.mktime(tt)
tt = _time.localtime(stamp)
return tt.tm_isdst > 0
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()
if days_to_go:
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)
class USTimeZone(tzinfo):
def __init__(self, hours, reprname, stdname, dstname):
self.stdoffset = timedelta(hours=hours)
self.reprname = reprname
self.stdname = stdname
self.dstname = dstname
def __repr__(self):
return self.reprname
def tzname(self, dt):
if self.dst(dt):
return self.dstname
else:
return self.stdname
def utcoffset(self, dt):
return self.stdoffset + self.dst(dt)
def dst(self, dt):
if dt is None or dt.tzinfo is None:
# An exception may be sensible here, in one or both cases.
# It depends on how you want to treat them. The default
# fromutc() implementation (called by the default astimezone()
# implementation) passes a datetime with dt.tzinfo is self.
return ZERO
assert dt.tzinfo is self
# Find first Sunday in April & the last in October.
start = first_sunday_on_or_after(DSTSTART.replace(year=dt.year))
end = first_sunday_on_or_after(DSTEND.replace(year=dt.year))
# Can't compare naive to aware objects, so strip the timezone from
# dt first.
if start <= dt.replace(tzinfo=None) < end:
return HOUR
else:
return ZERO
Eastern = USTimeZone(-5, "Eastern", "EST", "EDT")
#Central = USTimeZone(-6, "Central", "CST", "CDT")
#Mountain = USTimeZone(-7, "Mountain", "MST", "MDT")
Pacific = USTimeZone(-8, "Pacific", "PST", "PDT")
now = datetime.now()
print now.strftime("%a %b %d %X %z")
pst = now.replace(tzinfo=Pacific)
print pst.strftime("%a %b %d %X %z")
per ottenere l'ora corrente in un determinato fuso orario: 'ora = datetime.now (Pacifico)' ' – jfs