Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/isodate/tzinfo.py: 53%

1"""This module provides some datetime.tzinfo implementations. 

2 

3All those classes are taken from the Python documentation. 

4""" 

5 

6import time 

7from datetime import datetime, timedelta, tzinfo 

8from typing import Literal, Optional 

9 

10ZERO = timedelta(0) 

11# constant for zero time offset. 

12 

13 

14class Utc(tzinfo): 

15 """UTC 

16 

17 Universal time coordinated time zone. 

18 """ 

19 

20 def utcoffset(self, dt: Optional[datetime]) -> timedelta: 

21 """Return offset from UTC in minutes east of UTC, which is ZERO for UTC.""" 

22 return ZERO 

23 

24 def tzname(self, dt: Optional[datetime]) -> Literal["UTC"]: 

25 """Return the time zone name corresponding to the datetime object dt, 

26 as a string. 

27 """ 

28 return "UTC" 

29 

30 def dst(self, dt: Optional[datetime]) -> timedelta: 

31 """Return the daylight saving time (DST) adjustment, in minutes east 

32 of UTC. 

33 """ 

34 return ZERO 

35 

36 def __reduce__(self): 

37 """When unpickling a Utc object, return the default instance below, UTC.""" 

38 return _Utc, () 

39 

40 

41UTC = Utc() 

42# the default instance for UTC. 

43 

44 

45def _Utc() -> Utc: 

46 """Helper function for unpickling a Utc object.""" 

47 return UTC 

48 

49 

50class FixedOffset(tzinfo): 

51 """A class building tzinfo objects for fixed-offset time zones. 

52 

53 Note that FixedOffset(0, 0, "UTC") or FixedOffset() is a different way to 

54 build a UTC tzinfo object. 

55 """ 

56 

57 def __init__( 

58 self, offset_hours: float = 0, offset_minutes: float = 0, name: str = "UTC" 

59 ) -> None: 

60 """Initialise an instance with time offset and name. 

61 

62 The time offset should be positive for time zones east of UTC 

63 and negate for time zones west of UTC. 

64 """ 

65 self.__offset = timedelta(hours=offset_hours, minutes=offset_minutes) 

66 self.__name = name 

67 

68 def utcoffset(self, dt: Optional[datetime]) -> timedelta: 

69 """Return offset from UTC in minutes of UTC.""" 

70 return self.__offset 

71 

72 def tzname(self, dt: Optional[datetime]) -> str: 

73 """Return the time zone name corresponding to the datetime object dt, as a 

74 string. 

75 """ 

76 return self.__name 

77 

78 def dst(self, dt: Optional[datetime]) -> timedelta: 

79 """Return the daylight saving time (DST) adjustment, in minutes east of 

80 UTC. 

81 """ 

82 return ZERO 

83 

84 def __repr__(self) -> str: 

85 """Return nicely formatted repr string.""" 

86 return "<FixedOffset %r>" % self.__name 

87 

88 

89STDOFFSET = timedelta(seconds=-time.timezone) 

90# locale time zone offset 

91 

92# calculate local daylight saving offset if any. 

93DSTOFFSET = timedelta(seconds=-time.altzone) if time.daylight else STDOFFSET 

94 

95DSTDIFF = DSTOFFSET - STDOFFSET 

96# difference between local time zone and local DST time zone 

97 

98 

99class LocalTimezone(tzinfo): 

100 """A class capturing the platform's idea of local time.""" 

101 

102 def utcoffset(self, dt: Optional[datetime]) -> timedelta: 

103 """Return offset from UTC in minutes of UTC.""" 

104 if self._isdst(dt): 

105 return DSTOFFSET 

106 else: 

107 return STDOFFSET 

108 

109 def dst(self, dt: Optional[datetime]) -> timedelta: 

110 """Return daylight saving offset.""" 

111 if self._isdst(dt): 

112 return DSTDIFF 

113 else: 

114 return ZERO 

115 

116 def tzname(self, dt: Optional[datetime]) -> str: 

117 """Return the time zone name corresponding to the datetime object dt, as a 

118 string. 

119 """ 

120 return time.tzname[self._isdst(dt)] 

121 

122 def _isdst(self, dt: Optional[datetime]) -> bool: 

123 """Returns true if DST is active for given datetime object dt.""" 

124 if dt is None: 

125 raise Exception("datetime object dt was None!") 

126 tt = ( 

127 dt.year, 

128 dt.month, 

129 dt.day, 

130 dt.hour, 

131 dt.minute, 

132 dt.second, 

133 dt.weekday(), 

134 0, 

135 -1, 

136 ) 

137 stamp = time.mktime(tt) 

138 tt = time.localtime(stamp) 

139 return tt.tm_isdst > 0 

140 

141 

142# the default instance for local time zone. 

143LOCAL = LocalTimezone()