deprication of axis param in rolling functions

Author: dannyi96

pandas/core/generic.py

@@ -11911,12 +11911,29 @@ def rolling(
         center: bool_t = False,
         win_type: str | None = None,
         on: str | None = None,
-        axis: Axis = 0,
+        axis: Axis | lib.NoDefault = lib.no_default,
         closed: str | None = None,
         step: int | None = None,
         method: str = "single",
     ) -> Window | Rolling:
-        axis = self._get_axis_number(axis)
+        if axis is not lib.no_default:
+            axis = self._get_axis_number(axis)
+            if axis == 1:
+                warnings.warn(
+                    "DataFrame.rolling with axis=1 is deprecated. Do "
+                    "`frame.T.rolling(...)` without axis instead.",
+                    FutureWarning,
+                    stacklevel=find_stack_level(),
+                )
+            else:
+                warnings.warn(
+                    "The 'axis' keyword in DataFrame.rolling is deprecated and "
+                    "will be removed in a future version.",
+                    FutureWarning,
+                    stacklevel=find_stack_level(),
+                )
+        else:
+            axis = 0
 
         if win_type is not None:
             return Window(
@@ -11950,10 +11967,28 @@ def rolling(
     def expanding(
         self,
         min_periods: int = 1,
-        axis: Axis = 0,
+        axis: Axis | lib.NoDefault = lib.no_default,
         method: str = "single",
     ) -> Expanding:
-        axis = self._get_axis_number(axis)
+        if axis is not lib.no_default:
+            axis = self._get_axis_number(axis)
+            if axis == 1:
+                warnings.warn(
+                    "DataFrame.expanding with axis=1 is deprecated. Do "
+                    "`frame.T.expanding(...)` without axis instead.",
+                    FutureWarning,
+                    stacklevel=find_stack_level(),
+                )
+            else:
+                warnings.warn(
+                    "The 'axis' keyword in DataFrame.expanding is deprecated and "
+                    "will be removed in a future version.",
+                    FutureWarning,
+                    stacklevel=find_stack_level(),
+                )
+        else:
+            axis = 0
+
         return Expanding(self, min_periods=min_periods, axis=axis, method=method)
 
     @final
@@ -11967,11 +12002,29 @@ def ewm(
         min_periods: int | None = 0,
         adjust: bool_t = True,
         ignore_na: bool_t = False,
-        axis: Axis = 0,
+        axis: Axis | lib.NoDefault = lib.no_default,
         times: np.ndarray | DataFrame | Series | None = None,
         method: str = "single",
     ) -> ExponentialMovingWindow:
-        axis = self._get_axis_number(axis)
+        if axis is not lib.no_default:
+            axis = self._get_axis_number(axis)
+            if axis == 1:
+                warnings.warn(
+                    "DataFrame.ewm with axis=1 is deprecated. Do "
+                    "`frame.T.ewm(...)` without axis instead.",
+                    FutureWarning,
+                    stacklevel=find_stack_level(),
+                )
+            else:
+                warnings.warn(
+                    "The 'axis' keyword in DataFrame.ewm is deprecated and "
+                    "will be removed in a future version.",
+                    FutureWarning,
+                    stacklevel=find_stack_level(),
+                )
+        else:
+            axis = 0
+
         return ExponentialMovingWindow(
             self,
             com=com,

pandas/tests/window/test_api.py

@@ -129,7 +129,10 @@ def test_agg(step):
 def test_multi_axis_1_raises(func):
     # GH#46904
     df = DataFrame({"a": [1, 1, 2], "b": [3, 4, 5], "c": [6, 7, 8]})
-    r = df.rolling(window=3, axis=1)
+    warning_msg = "DataFrame.rolling with axis=1 is deprecated."
+
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        r = df.rolling(window=3, axis=1)
     with pytest.raises(NotImplementedError, match="axis other than 0 is not supported"):
         r.agg(func)
 
@@ -344,20 +347,29 @@ def test_dont_modify_attributes_after_methods(
 
 def test_centered_axis_validation(step):
     # ok
-    Series(np.ones(10)).rolling(window=3, center=True, axis=0, step=step).mean()
+    axis_0_warning_msg =  (
+        "The 'axis' keyword in DataFrame.rolling is deprecated and "
+        "will be removed in a future version."
+    )
+    axis_1_warning_msg = "DataFrame.rolling with axis=1 is deprecated."
+
+    with tm.assert_produces_warning(FutureWarning, match=axis_0_warning_msg):
+        Series(np.ones(10)).rolling(window=3, center=True, axis=0, step=step).mean()
 
     # bad axis
     msg = "No axis named 1 for object type Series"
     with pytest.raises(ValueError, match=msg):
         Series(np.ones(10)).rolling(window=3, center=True, axis=1, step=step).mean()
 
     # ok ok
-    DataFrame(np.ones((10, 10))).rolling(
-        window=3, center=True, axis=0, step=step
-    ).mean()
-    DataFrame(np.ones((10, 10))).rolling(
-        window=3, center=True, axis=1, step=step
-    ).mean()
+    with tm.assert_produces_warning(FutureWarning, match=axis_0_warning_msg):
+        DataFrame(np.ones((10, 10))).rolling(
+            window=3, center=True, axis=0, step=step
+        ).mean()
+    with tm.assert_produces_warning(FutureWarning, match=axis_1_warning_msg):
+        DataFrame(np.ones((10, 10))).rolling(
+            window=3, center=True, axis=1, step=step
+        ).mean()
 
     # bad axis
     msg = "No axis named 2 for object type DataFrame"

pandas/tests/window/test_apply.py

@@ -321,6 +321,9 @@ def test_center_reindex_frame(raw, frame):
 def test_axis1(raw):
     # GH 45912
     df = DataFrame([1, 2])
-    result = df.rolling(window=1, axis=1).apply(np.sum, raw=raw)
+    warning_msg = "DataFrame.rolling with axis=1 is deprecated."
+    
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        result = df.rolling(window=1, axis=1).apply(np.sum, raw=raw)
     expected = DataFrame([1.0, 2.0])
     tm.assert_frame_equal(result, expected)

pandas/tests/window/test_ewm.py

@@ -198,7 +198,9 @@ def test_float_dtype_ewma(func, expected, float_numpy_dtype):
     df = DataFrame(
         {0: range(5), 1: range(6, 11), 2: range(10, 20, 2)}, dtype=float_numpy_dtype
     )
-    e = df.ewm(alpha=0.5, axis=1)
+    warning_msg = "DataFrame.ewm with axis=1 is deprecated."
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        e = df.ewm(alpha=0.5, axis=1)
     result = getattr(e, func)()
 
     tm.assert_frame_equal(result, expected)
@@ -719,3 +721,18 @@ def test_numeric_only_corr_cov_series(kernel, use_arg, numeric_only, dtype):
         op2 = getattr(ewm2, kernel)
         expected = op2(*arg2, numeric_only=numeric_only)
         tm.assert_series_equal(result, expected)
+
+
+def test_df_ewn_axis_param_depr():
+    df = DataFrame({"a": [1], "b": 2, "c": 3})
+
+    warning_msg = (
+        "The 'axis' keyword in DataFrame.ewm is deprecated and "
+        "will be removed in a future version."
+    )
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        df.ewm(span=2, axis=0)
+
+    warning_msg = "DataFrame.ewm with axis=1 is deprecated."
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        df.ewm(span=2, axis=1)

pandas/tests/window/test_expanding.py

@@ -82,17 +82,22 @@ def test_missing_minp_zero():
 def test_expanding_axis(axis_frame):
     # see gh-23372.
     df = DataFrame(np.ones((10, 20)))
-    axis = df._get_axis_number(axis_frame)
-
+    axis = df._get_axis_number(axis_frame)         
     if axis == 0:
         expected = DataFrame(
             {i: [np.nan] * 2 + [float(j) for j in range(3, 11)] for i in range(20)}
         )
+        warning_msg = (
+            "The 'axis' keyword in DataFrame.expanding is deprecated and "
+            "will be removed in a future version."
+        )
     else:
         # axis == 1
         expected = DataFrame([[np.nan] * 2 + [float(i) for i in range(3, 21)]] * 10)
+        warning_msg = "DataFrame.expanding with axis=1 is deprecated."
 
-    result = df.expanding(3, axis=axis_frame).sum()
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        result = df.expanding(3, axis=axis_frame).sum()
     tm.assert_frame_equal(result, expected)
 
 
@@ -323,7 +328,12 @@ def test_expanding_corr_pairwise(frame):
 )
 def test_expanding_func(func, static_comp, frame_or_series):
     data = frame_or_series(np.array(list(range(10)) + [np.nan] * 10))
-    result = getattr(data.expanding(min_periods=1, axis=0), func)()
+    warning_msg = (
+        "The 'axis' keyword in DataFrame.expanding is deprecated and "
+        "will be removed in a future version."
+    )
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        result = getattr(data.expanding(min_periods=1, axis=0), func)()
     assert isinstance(result, frame_or_series)
 
     expected = static_comp(data[:11])
@@ -341,26 +351,36 @@ def test_expanding_func(func, static_comp, frame_or_series):
 def test_expanding_min_periods(func, static_comp):
     ser = Series(np.random.randn(50))
 
-    result = getattr(ser.expanding(min_periods=30, axis=0), func)()
+    warning_msg = (
+        "The 'axis' keyword in DataFrame.expanding is deprecated and "
+        "will be removed in a future version."
+    )
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        result = getattr(ser.expanding(min_periods=30, axis=0), func)()
     assert result[:29].isna().all()
     tm.assert_almost_equal(result.iloc[-1], static_comp(ser[:50]))
 
     # min_periods is working correctly
-    result = getattr(ser.expanding(min_periods=15, axis=0), func)()
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        result = getattr(ser.expanding(min_periods=15, axis=0), func)()
     assert isna(result.iloc[13])
     assert notna(result.iloc[14])
 
     ser2 = Series(np.random.randn(20))
-    result = getattr(ser2.expanding(min_periods=5, axis=0), func)()
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        result = getattr(ser2.expanding(min_periods=5, axis=0), func)()
     assert isna(result[3])
     assert notna(result[4])
 
     # min_periods=0
-    result0 = getattr(ser.expanding(min_periods=0, axis=0), func)()
-    result1 = getattr(ser.expanding(min_periods=1, axis=0), func)()
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        result0 = getattr(ser.expanding(min_periods=0, axis=0), func)()
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        result1 = getattr(ser.expanding(min_periods=1, axis=0), func)()
     tm.assert_almost_equal(result0, result1)
 
-    result = getattr(ser.expanding(min_periods=1, axis=0), func)()
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        result = getattr(ser.expanding(min_periods=1, axis=0), func)()
     tm.assert_almost_equal(result.iloc[-1], static_comp(ser[:50]))
 
 
@@ -693,3 +713,17 @@ def test_numeric_only_corr_cov_series(kernel, use_arg, numeric_only, dtype):
         op2 = getattr(expanding2, kernel)
         expected = op2(*arg2, numeric_only=numeric_only)
         tm.assert_series_equal(result, expected)
+
+def test_df_expanding_axis_param_depr():
+    df = DataFrame({"a": [1], "b": [2], "c": [3]})
+
+    warning_msg = (
+        "The 'axis' keyword in DataFrame.expanding is deprecated and "
+        "will be removed in a future version."
+    )
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        df.expanding(2, axis=0)
+
+    warning_msg = "DataFrame.expanding with axis=1 is deprecated."
+    with tm.assert_produces_warning(FutureWarning, match=warning_msg):
+        df.expanding(2, axis=1)