BUG: Offsets of offsets in holiday raise type error during usage

doc/source/whatsnew/v3.0.0.rst

@@ -280,6 +280,7 @@ Performance improvements
 
 Bug fixes
 ~~~~~~~~~
+- Fixed bug in :class:`Series.Holiday` that leads to a ``TypeError`` when using ``Holiday.dates`` with a ``Holiday`` that is initialized with ``offset`` of type ``list`` which itself references another Holiday's list of offsets. (:issue:`29049`)
 - Fixed bug in :class:`SparseDtype` for equal comparison with na fill value. (:issue:`54770`)
 - Fixed bug in :meth:`DataFrame.join` inconsistently setting result index name (:issue:`55815`)
 - Fixed bug in :meth:`DataFrame.to_string` that raised ``StopIteration`` with nested DataFrames. (:issue:`16098`)

pandas/tests/tseries/holiday/test_holiday.py

@@ -6,6 +6,7 @@
 from pandas import (
  DatetimeIndex,
  Series,
+ to_datetime,
 )
 import pandas._testing as tm
 
@@ -198,6 +199,33 @@ def test_holidays_within_dates(holiday, start, expected):
  ) == [utc.localize(dt) for dt in expected]
 
 
+def test_holidays_within_dates_offset_of_offset():
+ # see gh-29049
+ # Test that the offset of an offset is correctly applied to the holiday
+ # And that dates can be calculated
+ holiday1 = Holiday(
+ "Holiday1",
+ month=USThanksgivingDay.month,
+ day=USThanksgivingDay.day,
+ offset=[USThanksgivingDay.offset, DateOffset(1)],
+ )
+ holiday2 = Holiday(
+ "Holiday2",
+ month=holiday1.month,
+ day=holiday1.day,
+ offset=[holiday1.offset, DateOffset(3)],
+ )
+ # there shall be no lists of lists here
+ for offset in holiday2.offset:
+ assert isinstance(offset, DateOffset)
+
+ min_date, max_date = (to_datetime(x) for x in ["2017-11-1", "2018-11-30"])
+ expected_min, expected_max = DatetimeIndex(["2017-11-27", "2018-11-26"])
+ actual_min, actual_max = holiday2.dates(min_date, max_date)
+ assert actual_min == expected_min
+ assert actual_max == expected_max
+
+
 @pytest.mark.parametrize(
  "transform", [lambda x: x.strftime("%Y-%m-%d"), lambda x: Timestamp(x)]
 )

pandas/tseries/holiday.py

@@ -4,6 +4,11 @@
  datetime,
  timedelta,
 )
+from typing import (
+ TYPE_CHECKING,
+ Callable,
+ SupportsIndex,
+)
 import warnings
 
 from dateutil.relativedelta import (
@@ -33,6 +38,9 @@
  Easter,
 )
 
+if TYPE_CHECKING:
+ from pandas._libs.tslibs.offsets import BaseOffset
+
 
 def next_monday(dt: datetime) -> datetime:
  """
@@ -156,25 +164,33 @@ class Holiday:
  def __init__(
  self,
  name: str,
- year=None,
- month=None,
- day=None,
- offset=None,
- observance=None,
+ year: SupportsIndex | None = None,
+ month: SupportsIndex | None = None,
+ day: SupportsIndex | None = None,
+ offset: None | BaseOffset | list[BaseOffset | list[BaseOffset]] = None,
+ observance: Callable | None = None,
  start_date=None,
  end_date=None,
- days_of_week=None,
+ days_of_week: tuple | None = None,
  ) -> None:
  """
  Parameters
  ----------
  name : str
  Name of the holiday , defaults to class name
+ year: int
+ Year of the holiday
+ month: int
+ Month of the holiday
+ day: int
+ Day of the holiday
  offset : array of pandas.tseries.offsets or
  class from pandas.tseries.offsets
  computes offset from date
  observance: function
  computes when holiday is given a pandas Timestamp
+ start_date : datetime-like, optional
+ end_date : datetime-like, optional
  days_of_week:
  provide a tuple of days e.g (0,1,2,3,) for Monday Through Thursday
  Monday=0,..,Sunday=6
@@ -223,7 +239,18 @@ class from pandas.tseries.offsets
  self.year = year
  self.month = month
  self.day = day
- self.offset = offset
+ if isinstance(offset, list):
+ self.offset = []
+ for off in offset:
+ # check if we are handling offsets of another holiday
+ if isinstance(off, list):
+ self.offset.extend(np.ravel(off))
+ else:
+ # otherwise it should be a DateOffset, we do not support other
+ # array-like types
+ self.offset.append(off)
+ else:
+ self.offset = offset
  self.start_date = (
  Timestamp(start_date) if start_date is not None else start_date
  )