precommit

doc/source/whatsnew/v2.1.0.rst

@@ -123,12 +123,12 @@ Other enhancements
 - Added :meth:`ExtensionArray.interpolate` used by :meth:`Series.interpolate` and :meth:`DataFrame.interpolate` (:issue:`53659`)
 - Added ``engine_kwargs`` parameter to :meth:`DataFrame.to_excel` (:issue:`53220`)
 - Added a new parameter ``by_row`` to :meth:`Series.apply` and :meth:`DataFrame.apply`. When set to ``False`` the supplied callables will always operate on the whole Series or DataFrame (:issue:`53400`, :issue:`53601`).
+- :meth:`DataFrame.shift` and :meth:`Series.shift` now allow shifting by multiple periods by supplying a list of periods (:issue:`44424`)
 - Groupby aggregations (such as :meth:`DataFrameGroupby.sum`) now can preserve the dtype of the input instead of casting to ``float64`` (:issue:`44952`)
 - Improved error message when :meth:`DataFrameGroupBy.agg` failed (:issue:`52930`)
 - Many read/to_* functions, such as :meth:`DataFrame.to_pickle` and :func:`read_csv`, support forwarding compression arguments to lzma.LZMAFile (:issue:`52979`)
 - Performance improvement in :func:`concat` with homogeneous ``np.float64`` or ``np.float32`` dtypes (:issue:`52685`)
 - Performance improvement in :meth:`DataFrame.filter` when ``items`` is given (:issue:`52941`)
-- :meth:`DataFrame.shift` and :meth:`Series.shift` now allow shifting by multiple periods by supplying a list of periods (:issue:`44424`)
 -
 
 .. ---------------------------------------------------------------------------

pandas/core/frame.py

@@ -5511,15 +5511,18 @@ def shift(
 
         if is_list_like(periods):
             if axis == 1:
-                raise ValueError('If `periods` contains multiple shifts, `axis` cannot be 1.')
+                raise ValueError(
+                    "If `periods` contains multiple shifts, `axis` cannot be 1."
+                )
             if len(periods) == 0:
-                raise ValueError('If `periods` is an iterable, it cannot be empty.')
+                raise ValueError("If `periods` is an iterable, it cannot be empty.")
             from pandas.core.reshape.concat import concat
+
             result = []
             for period in periods:
                 if not isinstance(period, int):
                     raise TypeError(
-                        f"Value {period} in periods must be integer, but is type {type(period)}."
+                        f"Periods must be integer, but {period} is {type(period)}."
                     )
                 result.append(
                     super()

pandas/core/generic.py

@@ -15,7 +15,6 @@
     Any,
     Callable,
     ClassVar,
-    Iterable,
     Literal,
     NoReturn,
     cast,
@@ -198,6 +197,7 @@
 if TYPE_CHECKING:
     from collections.abc import (
         Hashable,
+        Iterable,
         Iterator,
         Mapping,
         Sequence,
@@ -10655,7 +10655,7 @@ def shift(
         if is_list_like(periods) and len(self.shape) == 1:
             return self.to_frame().shift(
                 periods=periods, freq=freq, axis=axis, fill_value=fill_value
-                )
+            )
 
         if freq is None:
             # when freq is None, data is shifted, index is not

pandas/tests/frame/methods/test_shift.py

@@ -678,22 +678,22 @@ def test_shift_with_iterable(self):
         tm.assert_frame_equal(expected, shifted)
 
         # test pd.Series
-        s: pd.Series = df['a']
-        tm.assert_frame_equal(s.shift(shifts), df[['a']].shift(shifts))
+        s: Series = df["a"]
+        tm.assert_frame_equal(s.shift(shifts), df[["a"]].shift(shifts))
 
         # test suffix
-        columns = df[['a']].shift(shifts, suffix='_suffix').columns
-        assert columns.tolist() == ['a_suffix_0', 'a_suffix_1', 'a_suffix_2']
+        columns = df[["a"]].shift(shifts, suffix="_suffix").columns
+        assert columns.tolist() == ["a_suffix_0", "a_suffix_1", "a_suffix_2"]
 
         # check bad inputs when doing multiple shifts
         msg = "If `periods` contains multiple shifts, `axis` cannot be 1."
         with pytest.raises(ValueError, match=msg):
             df.shift([1, 2], axis=1)
-        
-        msg = f"Value s in periods must be integer, but is type <class 'str'>."
+
+        msg = "Periods must be integer, but s is <class 'str'>."
         with pytest.raises(TypeError, match=msg):
-            df.shift(['s'])
+            df.shift(["s"])
 
-        msg = f"If `periods` is an iterable, it cannot be empty."
+        msg = "If `periods` is an iterable, it cannot be empty."
         with pytest.raises(ValueError, match=msg):
             df.shift([])