Coverage for jstark / features / first_and_last_date_of_period.py: 100%

1"""FirstAndLastDateOfPeriod class 

2 

3Helper class for figuring out dates relative to a given date 

4""" 

5 

6from datetime import date, timedelta 

7 

8import pendulum 

9 

10 

11class FirstAndLastDateOfPeriod: 

12 """Encapsulate all the logic to determine first and last date 

13 of a period that includes the supplied date 

14 """ 

15 

16 def __init__( 

17 self, date_in_period: date, first_day_of_week: str | None = None 

18 ) -> None: 

19 self._date_in_period = date_in_period 

20 self._weekdays = [ 

21 "Monday", 

22 "Tuesday", 

23 "Wednesday", 

24 "Thursday", 

25 "Friday", 

26 "Saturday", 

27 "Sunday", 

28 ] 

29 if first_day_of_week is None: 

30 # use what python determines to be the first day of the week 

31 first_day_of_week = ( 

32 date.today() - timedelta(date.today().weekday()) 

33 ).strftime("%A") 

34 if first_day_of_week not in self._weekdays: 

35 raise ValueError(f"first_day_of_week must be one of {self._weekdays}") 

36 self._first_day_of_week = first_day_of_week 

37 

38 @property 

39 def first_date_in_week(self) -> date: 

40 current_weekday_index = self._weekdays.index( 

41 self._date_in_period.strftime("%A") 

42 ) 

43 first_day_index = self._weekdays.index(self._first_day_of_week) 

44 # Number of days to subtract to get to the first day of this week (may be 0) 

45 days_to_subtract = (current_weekday_index - first_day_index) % 7 

46 return self._date_in_period - timedelta(days=days_to_subtract) 

47 

48 @property 

49 def last_date_in_week(self) -> date: 

50 return self.first_date_in_week + timedelta(days=6) 

51 

52 @property 

53 def first_date_in_month(self) -> date: 

54 return date(self._date_in_period.year, self._date_in_period.month, 1) 

55 

56 @property 

57 def last_date_in_month(self) -> date: 

58 first_of_month = pendulum.date( 

59 self._date_in_period.year, self._date_in_period.month, 1 

60 ) 

61 return first_of_month.add(months=1).subtract(days=1) 

62 

63 @property 

64 def first_date_in_quarter(self) -> date: 

65 match self._date_in_period.month: 

66 case 1 | 2 | 3: 

67 return date(self._date_in_period.year, 1, 1) 

68 case 4 | 5 | 6: 

69 return date(self._date_in_period.year, 4, 1) 

70 case 7 | 8 | 9: 

71 return date(self._date_in_period.year, 7, 1) 

72 case _: # all other months: 

73 return date(self._date_in_period.year, 10, 1) 

74 

75 @property 

76 def last_date_in_quarter(self) -> date: 

77 match self._date_in_period.month: 

78 case 1 | 2 | 3: 

79 return date(self._date_in_period.year, 3, 31) 

80 case 4 | 5 | 6: 

81 return date(self._date_in_period.year, 6, 30) 

82 case 7 | 8 | 9: 

83 return date(self._date_in_period.year, 9, 30) 

84 case _: # all other months: 

85 return date(self._date_in_period.year, 12, 31) 

86 

87 @property 

88 def first_date_in_year(self) -> date: 

89 return date(self._date_in_period.year, 1, 1) 

90 

91 @property 

92 def last_date_in_year(self) -> date: 

93 return date(self._date_in_period.year, 12, 31)