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annotate CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/lib/python3.8/site-packages/pytz/reference.py @ 69:33d812a61356

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planemo upload commit 2e9511a184a1ca667c7be0c6321a36dc4e3d116d
author jpayne
date Tue, 18 Mar 2025 17:55:14 -0400
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jpayne@69 1 '''
jpayne@69 2 Reference tzinfo implementations from the Python docs.
jpayne@69 3 Used for testing against as they are only correct for the years
jpayne@69 4 1987 to 2006. Do not use these for real code.
jpayne@69 5 '''
jpayne@69 6
jpayne@69 7 from datetime import tzinfo, timedelta, datetime
jpayne@69 8 from pytz import HOUR, ZERO, UTC
jpayne@69 9
jpayne@69 10 __all__ = [
jpayne@69 11 'FixedOffset',
jpayne@69 12 'LocalTimezone',
jpayne@69 13 'USTimeZone',
jpayne@69 14 'Eastern',
jpayne@69 15 'Central',
jpayne@69 16 'Mountain',
jpayne@69 17 'Pacific',
jpayne@69 18 'UTC'
jpayne@69 19 ]
jpayne@69 20
jpayne@69 21
jpayne@69 22 # A class building tzinfo objects for fixed-offset time zones.
jpayne@69 23 # Note that FixedOffset(0, "UTC") is a different way to build a
jpayne@69 24 # UTC tzinfo object.
jpayne@69 25 class FixedOffset(tzinfo):
jpayne@69 26 """Fixed offset in minutes east from UTC."""
jpayne@69 27
jpayne@69 28 def __init__(self, offset, name):
jpayne@69 29 self.__offset = timedelta(minutes=offset)
jpayne@69 30 self.__name = name
jpayne@69 31
jpayne@69 32 def utcoffset(self, dt):
jpayne@69 33 return self.__offset
jpayne@69 34
jpayne@69 35 def tzname(self, dt):
jpayne@69 36 return self.__name
jpayne@69 37
jpayne@69 38 def dst(self, dt):
jpayne@69 39 return ZERO
jpayne@69 40
jpayne@69 41
jpayne@69 42 import time as _time
jpayne@69 43
jpayne@69 44 STDOFFSET = timedelta(seconds=-_time.timezone)
jpayne@69 45 if _time.daylight:
jpayne@69 46 DSTOFFSET = timedelta(seconds=-_time.altzone)
jpayne@69 47 else:
jpayne@69 48 DSTOFFSET = STDOFFSET
jpayne@69 49
jpayne@69 50 DSTDIFF = DSTOFFSET - STDOFFSET
jpayne@69 51
jpayne@69 52
jpayne@69 53 # A class capturing the platform's idea of local time.
jpayne@69 54 class LocalTimezone(tzinfo):
jpayne@69 55
jpayne@69 56 def utcoffset(self, dt):
jpayne@69 57 if self._isdst(dt):
jpayne@69 58 return DSTOFFSET
jpayne@69 59 else:
jpayne@69 60 return STDOFFSET
jpayne@69 61
jpayne@69 62 def dst(self, dt):
jpayne@69 63 if self._isdst(dt):
jpayne@69 64 return DSTDIFF
jpayne@69 65 else:
jpayne@69 66 return ZERO
jpayne@69 67
jpayne@69 68 def tzname(self, dt):
jpayne@69 69 return _time.tzname[self._isdst(dt)]
jpayne@69 70
jpayne@69 71 def _isdst(self, dt):
jpayne@69 72 tt = (dt.year, dt.month, dt.day,
jpayne@69 73 dt.hour, dt.minute, dt.second,
jpayne@69 74 dt.weekday(), 0, -1)
jpayne@69 75 stamp = _time.mktime(tt)
jpayne@69 76 tt = _time.localtime(stamp)
jpayne@69 77 return tt.tm_isdst > 0
jpayne@69 78
jpayne@69 79 Local = LocalTimezone()
jpayne@69 80
jpayne@69 81
jpayne@69 82 def first_sunday_on_or_after(dt):
jpayne@69 83 days_to_go = 6 - dt.weekday()
jpayne@69 84 if days_to_go:
jpayne@69 85 dt += timedelta(days_to_go)
jpayne@69 86 return dt
jpayne@69 87
jpayne@69 88
jpayne@69 89 # In the US, DST starts at 2am (standard time) on the first Sunday in April.
jpayne@69 90 DSTSTART = datetime(1, 4, 1, 2)
jpayne@69 91 # and ends at 2am (DST time; 1am standard time) on the last Sunday of Oct.
jpayne@69 92 # which is the first Sunday on or after Oct 25.
jpayne@69 93 DSTEND = datetime(1, 10, 25, 1)
jpayne@69 94
jpayne@69 95
jpayne@69 96 # A complete implementation of current DST rules for major US time zones.
jpayne@69 97 class USTimeZone(tzinfo):
jpayne@69 98
jpayne@69 99 def __init__(self, hours, reprname, stdname, dstname):
jpayne@69 100 self.stdoffset = timedelta(hours=hours)
jpayne@69 101 self.reprname = reprname
jpayne@69 102 self.stdname = stdname
jpayne@69 103 self.dstname = dstname
jpayne@69 104
jpayne@69 105 def __repr__(self):
jpayne@69 106 return self.reprname
jpayne@69 107
jpayne@69 108 def tzname(self, dt):
jpayne@69 109 if self.dst(dt):
jpayne@69 110 return self.dstname
jpayne@69 111 else:
jpayne@69 112 return self.stdname
jpayne@69 113
jpayne@69 114 def utcoffset(self, dt):
jpayne@69 115 return self.stdoffset + self.dst(dt)
jpayne@69 116
jpayne@69 117 def dst(self, dt):
jpayne@69 118 if dt is None or dt.tzinfo is None:
jpayne@69 119 # An exception may be sensible here, in one or both cases.
jpayne@69 120 # It depends on how you want to treat them. The default
jpayne@69 121 # fromutc() implementation (called by the default astimezone()
jpayne@69 122 # implementation) passes a datetime with dt.tzinfo is self.
jpayne@69 123 return ZERO
jpayne@69 124 assert dt.tzinfo is self
jpayne@69 125
jpayne@69 126 # Find first Sunday in April & the last in October.
jpayne@69 127 start = first_sunday_on_or_after(DSTSTART.replace(year=dt.year))
jpayne@69 128 end = first_sunday_on_or_after(DSTEND.replace(year=dt.year))
jpayne@69 129
jpayne@69 130 # Can't compare naive to aware objects, so strip the timezone from
jpayne@69 131 # dt first.
jpayne@69 132 if start <= dt.replace(tzinfo=None) < end:
jpayne@69 133 return HOUR
jpayne@69 134 else:
jpayne@69 135 return ZERO
jpayne@69 136
jpayne@69 137 Eastern = USTimeZone(-5, "Eastern", "EST", "EDT")
jpayne@69 138 Central = USTimeZone(-6, "Central", "CST", "CDT")
jpayne@69 139 Mountain = USTimeZone(-7, "Mountain", "MST", "MDT")
jpayne@69 140 Pacific = USTimeZone(-8, "Pacific", "PST", "PDT")