Fixed apply_index (pandas-dev#35165)

Author: TomAugspurger

doc/source/reference/offset_frequency.rst

@@ -33,6 +33,7 @@ Methods
    :toctree: api/
 
     DateOffset.apply
+    DateOffset.apply_index
     DateOffset.copy
     DateOffset.isAnchored
     DateOffset.onOffset
@@ -117,6 +118,7 @@ Methods
    :toctree: api/
 
     BusinessHour.apply
+    BusinessHour.apply_index
     BusinessHour.copy
     BusinessHour.isAnchored
     BusinessHour.onOffset
@@ -201,6 +203,7 @@ Methods
    :toctree: api/
 
     CustomBusinessHour.apply
+    CustomBusinessHour.apply_index
     CustomBusinessHour.copy
     CustomBusinessHour.isAnchored
     CustomBusinessHour.onOffset
@@ -401,6 +404,7 @@ Methods
    :toctree: api/
 
     CustomBusinessMonthEnd.apply
+    CustomBusinessMonthEnd.apply_index
     CustomBusinessMonthEnd.copy
     CustomBusinessMonthEnd.isAnchored
     CustomBusinessMonthEnd.onOffset
@@ -447,6 +451,7 @@ Methods
    :toctree: api/
 
     CustomBusinessMonthBegin.apply
+    CustomBusinessMonthBegin.apply_index
     CustomBusinessMonthBegin.copy
     CustomBusinessMonthBegin.isAnchored
     CustomBusinessMonthBegin.onOffset
@@ -586,6 +591,7 @@ Methods
    :toctree: api/
 
     WeekOfMonth.apply
+    WeekOfMonth.apply_index
     WeekOfMonth.copy
     WeekOfMonth.isAnchored
     WeekOfMonth.onOffset
@@ -622,6 +628,7 @@ Methods
    :toctree: api/
 
     LastWeekOfMonth.apply
+    LastWeekOfMonth.apply_index
     LastWeekOfMonth.copy
     LastWeekOfMonth.isAnchored
     LastWeekOfMonth.onOffset
@@ -938,6 +945,7 @@ Methods
    :toctree: api/
 
     FY5253.apply
+    FY5253.apply_index
     FY5253.copy
     FY5253.get_rule_code_suffix
     FY5253.get_year_end
@@ -977,6 +985,7 @@ Methods
    :toctree: api/
 
     FY5253Quarter.apply
+    FY5253Quarter.apply_index
     FY5253Quarter.copy
     FY5253Quarter.get_rule_code_suffix
     FY5253Quarter.get_weeks
@@ -1013,6 +1022,7 @@ Methods
    :toctree: api/
 
     Easter.apply
+    Easter.apply_index
     Easter.copy
     Easter.isAnchored
     Easter.onOffset
@@ -1053,6 +1063,7 @@ Methods
     Tick.is_on_offset
     Tick.__call__
     Tick.apply
+    Tick.apply_index
 
 Day
 ---
@@ -1087,6 +1098,7 @@ Methods
     Day.is_on_offset
     Day.__call__
     Day.apply
+    Day.apply_index
 
 Hour
 ----
@@ -1121,6 +1133,7 @@ Methods
     Hour.is_on_offset
     Hour.__call__
     Hour.apply
+    Hour.apply_index
 
 Minute
 ------
@@ -1155,6 +1168,7 @@ Methods
     Minute.is_on_offset
     Minute.__call__
     Minute.apply
+    Minute.apply_index
 
 Second
 ------
@@ -1189,6 +1203,7 @@ Methods
     Second.is_on_offset
     Second.__call__
     Second.apply
+    Second.apply_index
 
 Milli
 -----
@@ -1223,6 +1238,7 @@ Methods
     Milli.is_on_offset
     Milli.__call__
     Milli.apply
+    Milli.apply_index
 
 Micro
 -----
@@ -1257,6 +1273,7 @@ Methods
     Micro.is_on_offset
     Micro.__call__
     Micro.apply
+    Micro.apply_index
 
 Nano
 ----
@@ -1291,6 +1308,7 @@ Methods
     Nano.is_on_offset
     Nano.__call__
     Nano.apply
+    Nano.apply_index
 
 .. _api.frequencies:
 

doc/source/whatsnew/v1.1.0.rst

@@ -787,6 +787,7 @@ Deprecations
 - :meth:`DatetimeIndex.week` and `DatetimeIndex.weekofyear` are deprecated and will be removed in a future version, use :meth:`DatetimeIndex.isocalendar().week` instead (:issue:`33595`)
 - :meth:`DatetimeArray.week` and `DatetimeArray.weekofyear` are deprecated and will be removed in a future version, use :meth:`DatetimeArray.isocalendar().week` instead (:issue:`33595`)
 - :meth:`DateOffset.__call__` is deprecated and will be removed in a future version, use ``offset + other`` instead (:issue:`34171`)
+- :meth:`~BusinessDay.apply_index` is deprecated and will be removed in a  future version. Use ``offset + other`` instead (:issue:`34580`)
 - :meth:`DataFrame.tshift` and :meth:`Series.tshift` are deprecated and will be removed in a future version, use :meth:`DataFrame.shift` and :meth:`Series.shift` instead (:issue:`11631`)
 - Indexing an :class:`Index` object with a float key is deprecated, and will
   raise an ``IndexError`` in the future. You can manually convert to an integer key

pandas/_libs/tslibs/offsets.pyx

@@ -86,19 +86,38 @@ cdef bint _is_normalized(datetime dt):
     return True
 
 
+def apply_wrapper_core(func, self, other) -> ndarray:
+    result = func(self, other)
+    result = np.asarray(result)
+
+    if self.normalize:
+        # TODO: Avoid circular/runtime import
+        from .vectorized import normalize_i8_timestamps
+        result = normalize_i8_timestamps(result.view("i8"), None)
+
+    return result
+
+
 def apply_index_wraps(func):
     # Note: normally we would use `@functools.wraps(func)`, but this does
     # not play nicely with cython class methods
-    def wrapper(self, other) -> np.ndarray:
+    def wrapper(self, other):
         # other is a DatetimeArray
+        result = apply_wrapper_core(func, self, other)
+        result = type(other)(result)
+        warnings.warn("'Offset.apply_index(other)' is deprecated. "
+                      "Use 'offset + other' instead.", FutureWarning)
+        return result
 
-        result = func(self, other)
-        result = np.asarray(result)
+    return wrapper
 
-        if self.normalize:
-            # TODO: Avoid circular/runtime import
-            from .vectorized import normalize_i8_timestamps
-            result = normalize_i8_timestamps(result.view("i8"), None)
+
+def apply_array_wraps(func):
+    # Note: normally we would use `@functools.wraps(func)`, but this does
+    # not play nicely with cython class methods
+    def wrapper(self, other) -> np.ndarray:
+        # other is a DatetimeArray
+        result = apply_wrapper_core(func, self, other)
         return result
 
     # do @functools.wraps(func) manually since it doesn't work on cdef funcs
@@ -515,19 +534,36 @@ cdef class BaseOffset:
         raises NotImplementedError for offsets without a
         vectorized implementation.
 
+        .. deprecated:: 1.1.0
+
+           Use ``offset + dtindex`` instead.
+
         Parameters
         ----------
         index : DatetimeIndex
 
         Returns
         -------
         DatetimeIndex
+
+        Raises
+        ------
+        NotImplementedError
+            When the specific offset subclass does not have a vectorized
+            implementation.
         """
         raise NotImplementedError(
             f"DateOffset subclass {type(self).__name__} "
             "does not have a vectorized implementation"
         )
 
+    @apply_array_wraps
+    def _apply_array(self, dtarr):
+        raise NotImplementedError(
+            f"DateOffset subclass {type(self).__name__} "
+            "does not have a vectorized implementation"
+        )
+
     def rollback(self, dt) -> datetime:
         """
         Roll provided date backward to next offset only if not on offset.
@@ -992,7 +1028,11 @@ cdef class RelativeDeltaOffset(BaseOffset):
         -------
         ndarray[datetime64[ns]]
         """
-        dt64other = np.asarray(dtindex)
+        return self._apply_array(dtindex)
+
+    @apply_array_wraps
+    def _apply_array(self, dtarr):
+        dt64other = np.asarray(dtarr)
         kwds = self.kwds
         relativedelta_fast = {
             "years",
@@ -1321,7 +1361,11 @@ cdef class BusinessDay(BusinessMixin):
 
     @apply_index_wraps
     def apply_index(self, dtindex):
-        i8other = dtindex.view("i8")
+        return self._apply_array(dtindex)
+
+    @apply_array_wraps
+    def _apply_array(self, dtarr):
+        i8other = dtarr.view("i8")
         return shift_bdays(i8other, self.n)
 
     def is_on_offset(self, dt: datetime) -> bool:
@@ -1804,8 +1848,12 @@ cdef class YearOffset(SingleConstructorOffset):
 
     @apply_index_wraps
     def apply_index(self, dtindex):
+        return self._apply_array(dtindex)
+
+    @apply_array_wraps
+    def _apply_array(self, dtarr):
         shifted = shift_quarters(
-            dtindex.view("i8"), self.n, self.month, self._day_opt, modby=12
+            dtarr.view("i8"), self.n, self.month, self._day_opt, modby=12
         )
         return shifted
 
@@ -1957,8 +2005,12 @@ cdef class QuarterOffset(SingleConstructorOffset):
 
     @apply_index_wraps
     def apply_index(self, dtindex):
+        return self._apply_array(dtindex)
+
+    @apply_array_wraps
+    def _apply_array(self, dtarr):
         shifted = shift_quarters(
-            dtindex.view("i8"), self.n, self.startingMonth, self._day_opt
+            dtarr.view("i8"), self.n, self.startingMonth, self._day_opt
         )
         return shifted
 
@@ -2072,7 +2124,11 @@ cdef class MonthOffset(SingleConstructorOffset):
 
     @apply_index_wraps
     def apply_index(self, dtindex):
-        shifted = shift_months(dtindex.view("i8"), self.n, self._day_opt)
+        return self._apply_array(dtindex)
+
+    @apply_array_wraps
+    def _apply_array(self, dtarr):
+        shifted = shift_months(dtarr.view("i8"), self.n, self._day_opt)
         return shifted
 
     cpdef __setstate__(self, state):
@@ -2209,8 +2265,14 @@ cdef class SemiMonthOffset(SingleConstructorOffset):
     @cython.wraparound(False)
     @cython.boundscheck(False)
     def apply_index(self, dtindex):
+        return self._apply_array(dtindex)
+
+    @apply_array_wraps
+    @cython.wraparound(False)
+    @cython.boundscheck(False)
+    def _apply_array(self, dtarr):
         cdef:
-            int64_t[:] i8other = dtindex.view("i8")
+            int64_t[:] i8other = dtarr.view("i8")
             Py_ssize_t i, count = len(i8other)
             int64_t val
             int64_t[:] out = np.empty(count, dtype="i8")
@@ -2368,12 +2430,16 @@ cdef class Week(SingleConstructorOffset):
 
     @apply_index_wraps
     def apply_index(self, dtindex):
+        return self._apply_array(dtindex)
+
+    @apply_array_wraps
+    def _apply_array(self, dtarr):
         if self.weekday is None:
             td = timedelta(days=7 * self.n)
             td64 = np.timedelta64(td, "ns")
-            return dtindex + td64
+            return dtarr + td64
         else:
-            i8other = dtindex.view("i8")
+            i8other = dtarr.view("i8")
             return self._end_apply_index(i8other)
 
     @cython.wraparound(False)
@@ -3146,6 +3212,9 @@ cdef class CustomBusinessDay(BusinessDay):
     def apply_index(self, dtindex):
         raise NotImplementedError
 
+    def _apply_array(self, dtarr):
+        raise NotImplementedError
+
     def is_on_offset(self, dt: datetime) -> bool:
         if self.normalize and not _is_normalized(dt):
             return False

pandas/core/arrays/datetimes.py

@@ -683,7 +683,7 @@ def _add_offset(self, offset):
                 values = self.tz_localize(None)
             else:
                 values = self
-            result = offset.apply_index(values)
+            result = offset._apply_array(values)
             result = DatetimeArray._simple_new(result)
             result = result.tz_localize(self.tz)
 

pandas/tests/tseries/offsets/test_offsets.py

@@ -3656,14 +3656,19 @@ def test_offset(self, case):
 
     @pytest.mark.parametrize("case", offset_cases)
     def test_apply_index(self, case):
+        # https://github.com/pandas-dev/pandas/issues/34580
         offset, cases = case
         s = DatetimeIndex(cases.keys())
+        exp = DatetimeIndex(cases.values())
+
         with tm.assert_produces_warning(None):
             # GH#22535 check that we don't get a FutureWarning from adding
             # an integer array to PeriodIndex
             result = offset + s
+        tm.assert_index_equal(result, exp)
 
-        exp = DatetimeIndex(cases.values())
+        with tm.assert_produces_warning(FutureWarning):
+            result = offset.apply_index(s)
         tm.assert_index_equal(result, exp)
 
     on_offset_cases = [