Update observed rules: add holiday removal support (#1796)

holidays/countries/angola.py

@@ -12,7 +12,7 @@
 
 from datetime import date
 from gettext import gettext as tr
-from typing import Tuple
+from typing import Optional, Tuple
 
 from holidays.calendars.gregorian import AUG, SEP
 from holidays.groups import ChristianHolidays, InternationalHolidays, StaticHolidays
@@ -59,7 +59,7 @@ def _is_observed(self, dt: date) -> bool:
         # it rolls over to the following Monday.
         return dt >= date(1996, SEP, 27)
 
-    def _add_observed(self, dt: date, **kwargs) -> Tuple[bool, date]:
+    def _add_observed(self, dt: date, **kwargs) -> Tuple[bool, Optional[date]]:
         # As per Law # #11/18, from 2018/9/10, when public holiday falls on Tuesday or Thursday,
         # the Monday or Friday is also a holiday.
         kwargs.setdefault(

holidays/countries/canada.py

@@ -12,6 +12,7 @@
 
 from datetime import date
 from gettext import gettext as tr
+from typing import Optional
 
 from holidays.calendars.gregorian import MAR, APR, JUN, JUL, SEP
 from holidays.constants import GOVERNMENT, OPTIONAL, PUBLIC
@@ -69,7 +70,7 @@ def __init__(self, *args, **kwargs):
         kwargs.setdefault("observed_rule", SAT_SUN_TO_NEXT_MON)
         super().__init__(*args, **kwargs)
 
-    def _get_nearest_monday(self, *args) -> date:
+    def _get_nearest_monday(self, *args) -> Optional[date]:
         return self._get_observed_date(date(self._year, *args), rule=ALL_TO_NEAREST_MON)
 
     def _add_statutory_holidays(self):

holidays/countries/jersey.py

@@ -11,7 +11,7 @@
 #  License: MIT (see LICENSE file)
 
 from datetime import date
-from typing import Tuple
+from typing import Optional, Tuple
 
 from holidays.calendars.gregorian import JAN, APR, MAY, JUN, JUL, SEP, OCT, DEC
 from holidays.groups import ChristianHolidays, InternationalHolidays, StaticHolidays
@@ -54,7 +54,7 @@ def __init__(self, *args, **kwargs):
         kwargs.setdefault("observed_rule", SAT_SUN_TO_NEXT_WORKDAY)
         ObservedHolidayBase.__init__(self, *args, **kwargs)
 
-    def _add_observed(self, dt: date, **kwargs) -> Tuple[bool, date]:
+    def _add_observed(self, dt: date, **kwargs) -> Tuple[bool, Optional[date]]:
         # Prior to 2004, in-lieu are only given for Sundays.
         # https://www.jerseylaw.je/laws/enacted/Pages/RO-123-2004.aspx
         kwargs.setdefault(

holidays/countries/new_zealand.py

@@ -11,6 +11,7 @@
 #  License: MIT (see LICENSE file)
 
 from datetime import date
+from typing import Optional
 
 from holidays.calendars.gregorian import JAN, FEB, MAR, JUN, JUL, SEP, NOV, DEC, _timedelta
 from holidays.groups import ChristianHolidays, InternationalHolidays, StaticHolidays
@@ -74,7 +75,7 @@ def __init__(self, *args, **kwargs):
         kwargs.setdefault("observed_rule", SAT_SUN_TO_NEXT_MON)
         super().__init__(*args, **kwargs)
 
-    def _get_nearest_monday(self, *args) -> date:
+    def _get_nearest_monday(self, *args) -> Optional[date]:
         dt = args if len(args) > 1 else args[0]
         dt = dt if isinstance(dt, date) else date(self._year, *dt)
         return self._get_observed_date(dt, rule=ALL_TO_NEAREST_MON)

holidays/observed_holiday_base.py

@@ -17,7 +17,7 @@
 from holidays.holiday_base import DateArg, HolidayBase
 
 
-class ObservedRule(Dict[int, int]):
+class ObservedRule(Dict[int, Optional[int]]):
     __slots__ = ()
 
     def __add__(self, other):
@@ -113,18 +113,23 @@ def _get_next_workday(self, dt: date, delta: int = +1) -> date:
                 return dt_work
         return dt
 
-    def _get_observed_date(self, dt: date, rule: ObservedRule) -> date:
+    def _get_observed_date(self, dt: date, rule: ObservedRule) -> Optional[date]:
         delta = rule.get(dt.weekday(), 0)
-        if delta != 0:
-            if abs(delta) == 7:
-                dt = self._get_next_workday(dt, delta // 7)
-            else:
-                dt = _timedelta(dt, delta)
+        if delta:
+            return (
+                self._get_next_workday(dt, delta // 7)
+                if abs(delta) == 7
+                else _timedelta(dt, delta)
+            )
+        # Goes after `if delta` case as a less probable.
+        elif delta is None:
+            return None
+
         return dt
 
     def _add_observed(
         self, dt: DateArg, name: Optional[str] = None, rule: Optional[ObservedRule] = None
-    ) -> Tuple[bool, date]:
+    ) -> Tuple[bool, Optional[date]]:
         dt = dt if isinstance(dt, date) else date(self._year, *dt)
 
         if not self.observed or not self._is_observed(dt):
@@ -134,6 +139,11 @@ def _add_observed(
         if dt_observed == dt:
             return False, dt
 
+        # SAT_TO_NONE and similar cases.
+        if dt_observed is None:
+            self.pop(dt)
+            return False, None
+
         estimated_label = self.tr(getattr(self, "estimated_label", ""))
         observed_label = self.tr(
             getattr(
@@ -158,7 +168,9 @@ def _add_observed(
 
         return True, dt_observed
 
-    def _move_holiday(self, dt: date, rule: Optional[ObservedRule] = None) -> Tuple[bool, date]:
+    def _move_holiday(
+        self, dt: date, rule: Optional[ObservedRule] = None
+    ) -> Tuple[bool, Optional[date]]:
         is_observed, dt_observed = self._add_observed(dt, rule=rule)
         if is_observed:
             self.pop(dt)

tests/test_observed_holiday_base.py

@@ -0,0 +1,56 @@
+#  holidays
+#  --------
+#  A fast, efficient Python library for generating country, province and state
+#  specific sets of holidays on the fly. It aims to make determining whether a
+#  specific date is a holiday as fast and flexible as possible.
+#
+#  Authors: Vacanza Team and individual contributors (see AUTHORS file)
+#           dr-prodigy <dr.prodigy.github@gmail.com> (c) 2017-2023
+#           ryanss <ryanssdev@icloud.com> (c) 2014-2017
+#  Website: https://github.com/vacanza/python-holidays
+#  License: MIT (see LICENSE file)
+
+from datetime import date
+from unittest import TestCase
+
+from holidays.calendars.gregorian import MON, SUN
+from holidays.observed_holiday_base import ObservedHolidayBase, ObservedRule
+
+
+class TestObservedHolidayBase(TestCase):
+    SUNDAY = date(2024, 5, 12)
+    MONDAY = date(2024, 5, 13)
+    SUN_TO_NONE = ObservedRule({SUN: None})
+    MON_TO_TUE = ObservedRule({MON: +1})
+
+    def setUp(self):
+        self.ohb = ObservedHolidayBase(observed_rule=ObservedRule({MON: None}))
+        self.ohb.observed_label = "%s (Observed Label)"
+        self.ohb._populate(2024)
+
+    def test_get_observed_date(self):
+        self.assertIsNone(self.ohb._get_observed_date(self.SUNDAY, rule=self.SUN_TO_NONE))
+
+    def test_observed_rules(self):
+        self.assertEqual(
+            (False, None),
+            self.ohb._add_observed(
+                self.ohb._add_holiday("Test Holiday", self.SUNDAY), rule=self.SUN_TO_NONE
+            ),
+        )
+
+        self.assertEqual(
+            (True, date(2024, 5, 14)),
+            self.ohb._add_observed(
+                self.ohb._add_holiday("Test Holiday", self.MONDAY), rule=self.MON_TO_TUE
+            ),
+        )
+
+        self.assertEqual(
+            dict(self.ohb),
+            {
+                date(2024, 5, 13): "Test Holiday",
+                date(2024, 5, 14): "Test Holiday (Observed Label)",
+            },
+            self.ohb,
+        )