DEP: Enforce deprecation of pad/backfill for groupby and resample (#49081)

* DEP: Enforce deprecation of pad/backfill for groupby and resample

* Remove test

* Add whatsnew

Author: phofl

doc/source/reference/groupby.rst

@@ -65,7 +65,6 @@ Function application
 
    DataFrameGroupBy.all
    DataFrameGroupBy.any
-   DataFrameGroupBy.backfill
    DataFrameGroupBy.bfill
    DataFrameGroupBy.corr
    DataFrameGroupBy.corrwith
@@ -94,7 +93,6 @@ Function application
    DataFrameGroupBy.nth
    DataFrameGroupBy.nunique
    DataFrameGroupBy.ohlc
-   DataFrameGroupBy.pad
    DataFrameGroupBy.pct_change
    DataFrameGroupBy.prod
    DataFrameGroupBy.quantile
@@ -120,7 +118,6 @@ Function application
 
    SeriesGroupBy.all
    SeriesGroupBy.any
-   SeriesGroupBy.backfill
    SeriesGroupBy.bfill
    SeriesGroupBy.corr
    SeriesGroupBy.count
@@ -153,7 +150,6 @@ Function application
    SeriesGroupBy.nunique
    SeriesGroupBy.unique
    SeriesGroupBy.ohlc
-   SeriesGroupBy.pad
    SeriesGroupBy.pct_change
    SeriesGroupBy.prod
    SeriesGroupBy.quantile

doc/source/reference/resampling.rst

@@ -35,9 +35,7 @@ Upsampling
    :toctree: api/
 
    Resampler.ffill
-   Resampler.backfill
    Resampler.bfill
-   Resampler.pad
    Resampler.nearest
    Resampler.fillna
    Resampler.asfreq

doc/source/whatsnew/v2.0.0.rst

@@ -145,7 +145,7 @@ Deprecations
 Removal of prior version deprecations/changes
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 - Disallow passing non-round floats to :class:`Timestamp` with ``unit="M"`` or ``unit="Y"`` (:issue:`47266`)
--
+- Remove :meth:`DataFrameGroupBy.pad` and :meth:`DataFrameGroupBy.backfill` (:issue:`45076`)
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_200.performance:

pandas/core/groupby/base.py

@@ -73,7 +73,6 @@ def maybe_normalize_deprecated_kernels(kernel) -> Literal["bfill", "ffill"]:
 
 transformation_kernels = frozenset(
     [
-        "backfill",
         "bfill",
         "cumcount",
         "cummax",
@@ -84,7 +83,6 @@ def maybe_normalize_deprecated_kernels(kernel) -> Literal["bfill", "ffill"]:
         "ffill",
         "fillna",
         "ngroup",
-        "pad",
         "pct_change",
         "rank",
         "shift",

pandas/core/groupby/groupby.py

@@ -2936,31 +2936,6 @@ def ffill(self, limit=None):
         """
         return self._fill("ffill", limit=limit)
 
-    def pad(self, limit=None):
-        """
-        Forward fill the values.
-
-        .. deprecated:: 1.4
-            Use ffill instead.
-
-        Parameters
-        ----------
-        limit : int, optional
-            Limit of how many values to fill.
-
-        Returns
-        -------
-        Series or DataFrame
-            Object with missing values filled.
-        """
-        warnings.warn(
-            "pad is deprecated and will be removed in a future version. "
-            "Use ffill instead.",
-            FutureWarning,
-            stacklevel=find_stack_level(),
-        )
-        return self.ffill(limit=limit)
-
     @final
     @Substitution(name="groupby")
     def bfill(self, limit=None):
@@ -2986,31 +2961,6 @@ def bfill(self, limit=None):
         """
         return self._fill("bfill", limit=limit)
 
-    def backfill(self, limit=None):
-        """
-        Backward fill the values.
-
-        .. deprecated:: 1.4
-            Use bfill instead.
-
-        Parameters
-        ----------
-        limit : int, optional
-            Limit of how many values to fill.
-
-        Returns
-        -------
-        Series or DataFrame
-            Object with missing values filled.
-        """
-        warnings.warn(
-            "backfill is deprecated and will be removed in a future version. "
-            "Use bfill instead.",
-            FutureWarning,
-            stacklevel=find_stack_level(),
-        )
-        return self.bfill(limit=limit)
-
     @final
     @Substitution(name="groupby")
     @Substitution(see_also=_common_see_also)

pandas/core/resample.py

@@ -11,7 +11,6 @@
     final,
     no_type_check,
 )
-import warnings
 
 import numpy as np
 
@@ -50,7 +49,6 @@
     deprecate_nonkeyword_arguments,
     doc,
 )
-from pandas.util._exceptions import find_stack_level
 
 from pandas.core.dtypes.generic import (
     ABCDataFrame,
@@ -562,30 +560,6 @@ def ffill(self, limit=None):
         """
         return self._upsample("ffill", limit=limit)
 
-    def pad(self, limit=None):
-        """
-        Forward fill the values.
-
-        .. deprecated:: 1.4
-            Use ffill instead.
-
-        Parameters
-        ----------
-        limit : int, optional
-            Limit of how many values to fill.
-
-        Returns
-        -------
-        An upsampled Series.
-        """
-        warnings.warn(
-            "pad is deprecated and will be removed in a future version. "
-            "Use ffill instead.",
-            FutureWarning,
-            stacklevel=find_stack_level(),
-        )
-        return self.ffill(limit=limit)
-
     def nearest(self, limit=None):
         """
         Resample by using the nearest value.
@@ -748,31 +722,6 @@ def bfill(self, limit=None):
         """
         return self._upsample("bfill", limit=limit)
 
-    def backfill(self, limit=None):
-        """
-        Backward fill the values.
-
-        .. deprecated:: 1.4
-            Use bfill instead.
-
-        Parameters
-        ----------
-        limit : int, optional
-            Limit of how many values to fill.
-
-        Returns
-        -------
-        Series, DataFrame
-            An upsampled Series or DataFrame with backward filled NaN values.
-        """
-        warnings.warn(
-            "backfill is deprecated and will be removed in a future version. "
-            "Use bfill instead.",
-            FutureWarning,
-            stacklevel=find_stack_level(),
-        )
-        return self.bfill(limit=limit)
-
     def fillna(self, method, limit=None):
         """
         Fill missing values introduced by upsampling.

pandas/tests/groupby/test_allowlist.py

@@ -217,8 +217,6 @@ def test_tab_completion(mframe):
         "idxmin",
         "ffill",
         "bfill",
-        "pad",
-        "backfill",
         "rolling",
         "expanding",
         "pipe",

pandas/tests/groupby/test_groupby.py

@@ -2778,15 +2778,6 @@ def test_rolling_wrong_param_min_period():
         test_df.groupby("name")["val"].rolling(window=2, min_period=1).sum()
 
 
-def test_pad_backfill_deprecation():
-    # GH 33396
-    s = Series([1, 2, 3])
-    with tm.assert_produces_warning(FutureWarning, match="backfill"):
-        s.groupby(level=0).backfill()
-    with tm.assert_produces_warning(FutureWarning, match="pad"):
-        s.groupby(level=0).pad()
-
-
 def test_by_column_values_with_same_starting_value():
     # GH29635
     df = DataFrame(

pandas/tests/resample/test_deprecated.py

@@ -305,12 +305,3 @@ def test_interpolate_posargs_deprecation():
 
     expected.index._data.freq = "3s"
     tm.assert_series_equal(result, expected)
-
-
-def test_pad_backfill_deprecation():
-    # GH 33396
-    s = Series([1, 2, 3], index=date_range("20180101", periods=3, freq="h"))
-    with tm.assert_produces_warning(FutureWarning, match="backfill"):
-        s.resample("30min").backfill()
-    with tm.assert_produces_warning(FutureWarning, match="pad"):
-        s.resample("30min").pad()