Python code coverage for Doc/includes/tzinfo-examples.py

#	count	content
1	n/a	from datetime import tzinfo, timedelta, datetime, timezone
2	n/a
3	n/a	ZERO = timedelta(0)
4	n/a	HOUR = timedelta(hours=1)
5	n/a	SECOND = timedelta(seconds=1)
6	n/a
7	n/a	# A class capturing the platform's idea of local time.
8	n/a	# (May result in wrong values on historical times in
9	n/a	# timezones where UTC offset and/or the DST rules had
10	n/a	# changed in the past.)
11	n/a	import time as _time
12	n/a
13	n/a	STDOFFSET = timedelta(seconds = -_time.timezone)
14	n/a	if _time.daylight:
15	n/a	DSTOFFSET = timedelta(seconds = -_time.altzone)
16	n/a	else:
17	n/a	DSTOFFSET = STDOFFSET
18	n/a
19	n/a	DSTDIFF = DSTOFFSET - STDOFFSET
20	n/a
21	n/a	class LocalTimezone(tzinfo):
22	n/a
23	n/a	def fromutc(self, dt):
24	n/a	assert dt.tzinfo is self
25	n/a	stamp = (dt - datetime(1970, 1, 1, tzinfo=self)) // SECOND
26	n/a	args = _time.localtime(stamp)[:6]
27	n/a	dst_diff = DSTDIFF // SECOND
28	n/a	# Detect fold
29	n/a	fold = (args == _time.localtime(stamp - dst_diff))
30	n/a	return datetime(*args, microsecond=dt.microsecond,
31	n/a	tzinfo=self, fold=fold)
32	n/a
33	n/a	def utcoffset(self, dt):
34	n/a	if self._isdst(dt):
35	n/a	return DSTOFFSET
36	n/a	else:
37	n/a	return STDOFFSET
38	n/a
39	n/a	def dst(self, dt):
40	n/a	if self._isdst(dt):
41	n/a	return DSTDIFF
42	n/a	else:
43	n/a	return ZERO
44	n/a
45	n/a	def tzname(self, dt):
46	n/a	return _time.tzname[self._isdst(dt)]
47	n/a
48	n/a	def _isdst(self, dt):
49	n/a	tt = (dt.year, dt.month, dt.day,
50	n/a	dt.hour, dt.minute, dt.second,
51	n/a	dt.weekday(), 0, 0)
52	n/a	stamp = _time.mktime(tt)
53	n/a	tt = _time.localtime(stamp)
54	n/a	return tt.tm_isdst > 0
55	n/a
56	n/a	Local = LocalTimezone()
57	n/a
58	n/a
59	n/a	# A complete implementation of current DST rules for major US time zones.
60	n/a
61	n/a	def first_sunday_on_or_after(dt):
62	n/a	days_to_go = 6 - dt.weekday()
63	n/a	if days_to_go:
64	n/a	dt += timedelta(days_to_go)
65	n/a	return dt
66	n/a
67	n/a
68	n/a	# US DST Rules
69	n/a	#
70	n/a	# This is a simplified (i.e., wrong for a few cases) set of rules for US
71	n/a	# DST start and end times. For a complete and up-to-date set of DST rules
72	n/a	# and timezone definitions, visit the Olson Database (or try pytz):
73	n/a	# http://www.twinsun.com/tz/tz-link.htm
74	n/a	# http://sourceforge.net/projects/pytz/ (might not be up-to-date)
75	n/a	#
76	n/a	# In the US, since 2007, DST starts at 2am (standard time) on the second
77	n/a	# Sunday in March, which is the first Sunday on or after Mar 8.
78	n/a	DSTSTART_2007 = datetime(1, 3, 8, 2)
79	n/a	# and ends at 2am (DST time) on the first Sunday of Nov.
80	n/a	DSTEND_2007 = datetime(1, 11, 1, 2)
81	n/a	# From 1987 to 2006, DST used to start at 2am (standard time) on the first
82	n/a	# Sunday in April and to end at 2am (DST time) on the last
83	n/a	# Sunday of October, which is the first Sunday on or after Oct 25.
84	n/a	DSTSTART_1987_2006 = datetime(1, 4, 1, 2)
85	n/a	DSTEND_1987_2006 = datetime(1, 10, 25, 2)
86	n/a	# From 1967 to 1986, DST used to start at 2am (standard time) on the last
87	n/a	# Sunday in April (the one on or after April 24) and to end at 2am (DST time)
88	n/a	# on the last Sunday of October, which is the first Sunday
89	n/a	# on or after Oct 25.
90	n/a	DSTSTART_1967_1986 = datetime(1, 4, 24, 2)
91	n/a	DSTEND_1967_1986 = DSTEND_1987_2006
92	n/a
93	n/a	def us_dst_range(year):
94	n/a	# Find start and end times for US DST. For years before 1967, return
95	n/a	# start = end for no DST.
96	n/a	if 2006 < year:
97	n/a	dststart, dstend = DSTSTART_2007, DSTEND_2007
98	n/a	elif 1986 < year < 2007:
99	n/a	dststart, dstend = DSTSTART_1987_2006, DSTEND_1987_2006
100	n/a	elif 1966 < year < 1987:
101	n/a	dststart, dstend = DSTSTART_1967_1986, DSTEND_1967_1986
102	n/a	else:
103	n/a	return (datetime(year, 1, 1), ) * 2
104	n/a
105	n/a	start = first_sunday_on_or_after(dststart.replace(year=year))
106	n/a	end = first_sunday_on_or_after(dstend.replace(year=year))
107	n/a	return start, end
108	n/a
109	n/a
110	n/a	class USTimeZone(tzinfo):
111	n/a
112	n/a	def __init__(self, hours, reprname, stdname, dstname):
113	n/a	self.stdoffset = timedelta(hours=hours)
114	n/a	self.reprname = reprname
115	n/a	self.stdname = stdname
116	n/a	self.dstname = dstname
117	n/a
118	n/a	def __repr__(self):
119	n/a	return self.reprname
120	n/a
121	n/a	def tzname(self, dt):
122	n/a	if self.dst(dt):
123	n/a	return self.dstname
124	n/a	else:
125	n/a	return self.stdname
126	n/a
127	n/a	def utcoffset(self, dt):
128	n/a	return self.stdoffset + self.dst(dt)
129	n/a
130	n/a	def dst(self, dt):
131	n/a	if dt is None or dt.tzinfo is None:
132	n/a	# An exception may be sensible here, in one or both cases.
133	n/a	# It depends on how you want to treat them. The default
134	n/a	# fromutc() implementation (called by the default astimezone()
135	n/a	# implementation) passes a datetime with dt.tzinfo is self.
136	n/a	return ZERO
137	n/a	assert dt.tzinfo is self
138	n/a	start, end = us_dst_range(dt.year)
139	n/a	# Can't compare naive to aware objects, so strip the timezone from
140	n/a	# dt first.
141	n/a	dt = dt.replace(tzinfo=None)
142	n/a	if start + HOUR <= dt < end - HOUR:
143	n/a	# DST is in effect.
144	n/a	return HOUR
145	n/a	if end - HOUR <= dt < end:
146	n/a	# Fold (an ambiguous hour): use dt.fold to disambiguate.
147	n/a	return ZERO if dt.fold else HOUR
148	n/a	if start <= dt < start + HOUR:
149	n/a	# Gap (a non-existent hour): reverse the fold rule.
150	n/a	return HOUR if dt.fold else ZERO
151	n/a	# DST is off.
152	n/a	return ZERO
153	n/a
154	n/a	def fromutc(self, dt):
155	n/a	assert dt.tzinfo is self
156	n/a	start, end = us_dst_range(dt.year)
157	n/a	start = start.replace(tzinfo=self)
158	n/a	end = end.replace(tzinfo=self)
159	n/a	std_time = dt + self.stdoffset
160	n/a	dst_time = std_time + HOUR
161	n/a	if end <= dst_time < end + HOUR:
162	n/a	# Repeated hour
163	n/a	return std_time.replace(fold=1)
164	n/a	if std_time < start or dst_time >= end:
165	n/a	# Standard time
166	n/a	return std_time
167	n/a	if start <= std_time < end - HOUR:
168	n/a	# Daylight saving time
169	n/a	return dst_time
170	n/a
171	n/a
172	n/a	Eastern = USTimeZone(-5, "Eastern", "EST", "EDT")
173	n/a	Central = USTimeZone(-6, "Central", "CST", "CDT")
174	n/a	Mountain = USTimeZone(-7, "Mountain", "MST", "MDT")
175	n/a	Pacific = USTimeZone(-8, "Pacific", "PST", "PDT")