broaden if check; specify error message

Author: dontgoto

pandas/tests/tseries/holiday/test_holiday.py

@@ -280,7 +280,8 @@ def test_list_of_list_of_offsets_raises():
  day=USThanksgivingDay.day,
  offset=[USThanksgivingDay.offset, DateOffset(1)],
  )
- with pytest.raises(ValueError, match="Nested lists are not supported for offset"):
+ msg = "Only BaseOffsets and flat lists thereof are supported for offset."
+ with pytest.raises(ValueError, match=msg):
  Holiday(
  "Holiday2",
  month=holiday1.month,

pandas/tseries/holiday.py

@@ -4,10 +4,7 @@
  datetime,
  timedelta,
 )
-from typing import (
- TYPE_CHECKING,
- Callable,
-)
+from typing import Callable
 import warnings
 
 from dateutil.relativedelta import (
@@ -21,6 +18,7 @@
 )
 import numpy as np
 
+from pandas._libs.tslibs.offsets import BaseOffset
 from pandas.errors import PerformanceWarning
 
 from pandas import (
@@ -37,9 +35,6 @@
  Easter,
 )
 
-if TYPE_CHECKING:
- from pandas._libs.tslibs.offsets import BaseOffset
-
 
 def next_monday(dt: datetime) -> datetime:
  """
@@ -156,7 +151,6 @@ class Holiday:
  for observance.
  """
 
- offset: BaseOffset | list[BaseOffset] | None
  start_date: Timestamp | None
  end_date: Timestamp | None
  days_of_week: tuple[int, ...] | None
@@ -234,13 +228,19 @@ class from pandas.tseries.offsets, default None
  >>> July3rd
  Holiday: July 3rd (month=7, day=3, )
  """
- if offset is not None and observance is not None:
- raise NotImplementedError("Cannot use both offset and observance.")
- if isinstance(offset, list) and any(isinstance(off, list) for off in offset):
- raise ValueError(
- "Nested lists are not supported for offset. "
- "Flatten composite offsets of `Holiday.offset`s first."
- )
+ if offset is not None:
+ if observance is not None:
+ raise NotImplementedError("Cannot use both offset and observance.")
+ if not (
+ isinstance(offset, BaseOffset)
+ or (
+ isinstance(offset, list)
+ and all(isinstance(off, BaseOffset) for off in offset)
+ )
+ ):
+ raise ValueError(
+ "Only BaseOffsets and flat lists of them are supported for offset."
+ )
 
  self.name = name
  self.year = year