DEPR: Deprecate remaining copy usages (#57870)

* DEPR: Deprecate remaining copy usages

* Fixup

* Fixup tests

* Fixup tests

---------

Co-authored-by: Matthew Roeschke <[email protected]>

Author: 2 people

doc/source/whatsnew/v3.0.0.rst

@@ -173,6 +173,13 @@ will be removed in a future version:
 - :meth:`DataFrame.astype` / :meth:`Series.astype`
 - :meth:`DataFrame.reindex` / :meth:`Series.reindex`
 - :meth:`DataFrame.reindex_like` / :meth:`Series.reindex_like`
+- :meth:`DataFrame.set_axis` / :meth:`Series.set_axis`
+- :meth:`DataFrame.to_period` / :meth:`Series.to_period`
+- :meth:`DataFrame.to_timestamp` / :meth:`Series.to_timestamp`
+- :meth:`DataFrame.rename` / :meth:`Series.rename`
+- :meth:`DataFrame.transpose`
+- :meth:`DataFrame.swaplevel`
+- :meth:`DataFrame.merge` / :func:`pd.merge`
 
 Copy-on-Write utilizes a lazy copy mechanism that defers copying the data until
 necessary. Use ``.copy`` to trigger an eager copy. The copy keyword has no effect

pandas/core/frame.py

@@ -357,7 +357,7 @@
     of a string to indicate that the column name from `left` or
     `right` should be left as-is, with no suffix. At least one of the
     values must not be None.
-copy : bool, default True
+copy : bool, default False
     If False, avoid copy if possible.
 
     .. note::
@@ -371,6 +371,8 @@
 
         You can already get the future behavior and improvements through
         enabling copy on write ``pd.options.mode.copy_on_write = True``
+
+    .. deprecated:: 3.0.0
 indicator : bool or str, default False
     If True, adds a column to the output DataFrame called "_merge" with
     information on the source of each row. The column can be given a different
@@ -3576,7 +3578,11 @@ def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
             result = index_memory_usage._append(result)
         return result
 
-    def transpose(self, *args, copy: bool = False) -> DataFrame:
+    def transpose(
+        self,
+        *args,
+        copy: bool | lib.NoDefault = lib.no_default,
+    ) -> DataFrame:
         """
         Transpose index and columns.
 
@@ -3607,6 +3613,8 @@ def transpose(self, *args, copy: bool = False) -> DataFrame:
                 You can already get the future behavior and improvements through
                 enabling copy on write ``pd.options.mode.copy_on_write = True``
 
+            .. deprecated:: 3.0.0
+
         Returns
         -------
         DataFrame
@@ -3687,6 +3695,7 @@ def transpose(self, *args, copy: bool = False) -> DataFrame:
         1    object
         dtype: object
         """
+        self._check_copy_deprecation(copy)
         nv.validate_transpose(args, {})
         # construct the args
 
@@ -5062,9 +5071,9 @@ def set_axis(
         labels,
         *,
         axis: Axis = 0,
-        copy: bool | None = None,
+        copy: bool | lib.NoDefault = lib.no_default,
     ) -> DataFrame:
-        return super().set_axis(labels, axis=axis)
+        return super().set_axis(labels, axis=axis, copy=copy)
 
     @doc(
         NDFrame.reindex,
@@ -5313,7 +5322,7 @@ def rename(
         index: Renamer | None = ...,
         columns: Renamer | None = ...,
         axis: Axis | None = ...,
-        copy: bool | None = ...,
+        copy: bool | lib.NoDefault = lib.no_default,
         inplace: Literal[True],
         level: Level = ...,
         errors: IgnoreRaise = ...,
@@ -5327,7 +5336,7 @@ def rename(
         index: Renamer | None = ...,
         columns: Renamer | None = ...,
         axis: Axis | None = ...,
-        copy: bool | None = ...,
+        copy: bool | lib.NoDefault = lib.no_default,
         inplace: Literal[False] = ...,
         level: Level = ...,
         errors: IgnoreRaise = ...,
@@ -5341,7 +5350,7 @@ def rename(
         index: Renamer | None = ...,
         columns: Renamer | None = ...,
         axis: Axis | None = ...,
-        copy: bool | None = ...,
+        copy: bool | lib.NoDefault = lib.no_default,
         inplace: bool = ...,
         level: Level = ...,
         errors: IgnoreRaise = ...,
@@ -5354,7 +5363,7 @@ def rename(
         index: Renamer | None = None,
         columns: Renamer | None = None,
         axis: Axis | None = None,
-        copy: bool | None = None,
+        copy: bool | lib.NoDefault = lib.no_default,
         inplace: bool = False,
         level: Level | None = None,
         errors: IgnoreRaise = "ignore",
@@ -5384,7 +5393,7 @@ def rename(
         axis : {0 or 'index', 1 or 'columns'}, default 0
             Axis to target with ``mapper``. Can be either the axis name
             ('index', 'columns') or number (0, 1). The default is 'index'.
-        copy : bool, default True
+        copy : bool, default False
             Also copy underlying data.
 
             .. note::
@@ -5398,6 +5407,8 @@ def rename(
 
                 You can already get the future behavior and improvements through
                 enabling copy on write ``pd.options.mode.copy_on_write = True``
+
+            .. deprecated:: 3.0.0
         inplace : bool, default False
             Whether to modify the DataFrame rather than creating a new one.
             If True then value of copy is ignored.
@@ -5478,6 +5489,7 @@ def rename(
         2  2  5
         4  3  6
         """
+        self._check_copy_deprecation(copy)
         return super()._rename(
             mapper=mapper,
             index=index,
@@ -10657,10 +10669,12 @@ def merge(
         right_index: bool = False,
         sort: bool = False,
         suffixes: Suffixes = ("_x", "_y"),
-        copy: bool | None = None,
+        copy: bool | lib.NoDefault = lib.no_default,
         indicator: str | bool = False,
         validate: MergeValidate | None = None,
     ) -> DataFrame:
+        self._check_copy_deprecation(copy)
+
         from pandas.core.reshape.merge import merge
 
         return merge(
@@ -12462,7 +12476,7 @@ def to_timestamp(
         freq: Frequency | None = None,
         how: ToTimestampHow = "start",
         axis: Axis = 0,
-        copy: bool | None = None,
+        copy: bool | lib.NoDefault = lib.no_default,
     ) -> DataFrame:
         """
         Cast to DatetimeIndex of timestamps, at *beginning* of period.
@@ -12476,7 +12490,7 @@ def to_timestamp(
             vs. end.
         axis : {0 or 'index', 1 or 'columns'}, default 0
             The axis to convert (the index by default).
-        copy : bool, default True
+        copy : bool, default False
             If False then underlying input data is not copied.
 
             .. note::
@@ -12491,6 +12505,8 @@ def to_timestamp(
                 You can already get the future behavior and improvements through
                 enabling copy on write ``pd.options.mode.copy_on_write = True``
 
+            .. deprecated:: 3.0.0
+
         Returns
         -------
         DataFrame
@@ -12527,6 +12543,7 @@ def to_timestamp(
         >>> df2.index
         DatetimeIndex(['2023-01-31', '2024-01-31'], dtype='datetime64[ns]', freq=None)
         """
+        self._check_copy_deprecation(copy)
         new_obj = self.copy(deep=False)
 
         axis_name = self._get_axis_name(axis)
@@ -12540,7 +12557,10 @@ def to_timestamp(
         return new_obj
 
     def to_period(
-        self, freq: Frequency | None = None, axis: Axis = 0, copy: bool | None = None
+        self,
+        freq: Frequency | None = None,
+        axis: Axis = 0,
+        copy: bool | lib.NoDefault = lib.no_default,
     ) -> DataFrame:
         """
         Convert DataFrame from DatetimeIndex to PeriodIndex.
@@ -12554,7 +12574,7 @@ def to_period(
             Frequency of the PeriodIndex.
         axis : {0 or 'index', 1 or 'columns'}, default 0
             The axis to convert (the index by default).
-        copy : bool, default True
+        copy : bool, default False
             If False then underlying input data is not copied.
 
             .. note::
@@ -12569,6 +12589,8 @@ def to_period(
                 You can already get the future behavior and improvements through
                 enabling copy on write ``pd.options.mode.copy_on_write = True``
 
+            .. deprecated:: 3.0.0
+
         Returns
         -------
         DataFrame
@@ -12596,6 +12618,7 @@ def to_period(
         >>> idx.to_period("Y")
         PeriodIndex(['2001', '2002', '2003'], dtype='period[Y-DEC]')
         """
+        self._check_copy_deprecation(copy)
         new_obj = self.copy(deep=False)
 
         axis_name = self._get_axis_name(axis)

pandas/core/generic.py

@@ -398,7 +398,7 @@ def flags(self) -> Flags:
     def set_flags(
         self,
         *,
-        copy: bool = False,
+        copy: bool | lib.NoDefault = lib.no_default,
         allows_duplicate_labels: bool | None = None,
     ) -> Self:
         """
@@ -420,6 +420,8 @@ def set_flags(
 
                 You can already get the future behavior and improvements through
                 enabling copy on write ``pd.options.mode.copy_on_write = True``
+
+            .. deprecated:: 3.0.0
         allows_duplicate_labels : bool, optional
             Whether the returned object allows duplicate labels.
 
@@ -454,6 +456,7 @@ def set_flags(
         >>> df2.flags.allows_duplicate_labels
         False
         """
+        self._check_copy_deprecation(copy)
         df = self.copy(deep=False)
         if allows_duplicate_labels is not None:
             df.flags["allows_duplicate_labels"] = allows_duplicate_labels
@@ -679,7 +682,7 @@ def set_axis(
         labels,
         *,
         axis: Axis = 0,
-        copy: bool | None = None,
+        copy: bool | lib.NoDefault = lib.no_default,
     ) -> Self:
         """
         Assign desired index to given axis.
@@ -696,7 +699,7 @@ def set_axis(
             The axis to update. The value 0 identifies the rows. For `Series`
             this parameter is unused and defaults to 0.
 
-        copy : bool, default True
+        copy : bool, default False
             Whether to make a copy of the underlying data.
 
             .. note::
@@ -711,6 +714,8 @@ def set_axis(
                 You can already get the future behavior and improvements through
                 enabling copy on write ``pd.options.mode.copy_on_write = True``
 
+            .. deprecated:: 3.0.0
+
         Returns
         -------
         %(klass)s
@@ -720,6 +725,7 @@ def set_axis(
         --------
         %(klass)s.rename_axis : Alter the name of the index%(see_also_sub)s.
         """
+        self._check_copy_deprecation(copy)
         return self._set_axis_nocheck(labels, axis, inplace=False)
 
     @overload
@@ -948,7 +954,6 @@ def _rename(
         index: Renamer | None = ...,
         columns: Renamer | None = ...,
         axis: Axis | None = ...,
-        copy: bool | None = ...,
         inplace: Literal[False] = ...,
         level: Level | None = ...,
         errors: str = ...,
@@ -962,7 +967,6 @@ def _rename(
         index: Renamer | None = ...,
         columns: Renamer | None = ...,
         axis: Axis | None = ...,
-        copy: bool | None = ...,
         inplace: Literal[True],
         level: Level | None = ...,
         errors: str = ...,
@@ -976,7 +980,6 @@ def _rename(
         index: Renamer | None = ...,
         columns: Renamer | None = ...,
         axis: Axis | None = ...,
-        copy: bool | None = ...,
         inplace: bool,
         level: Level | None = ...,
         errors: str = ...,
@@ -990,7 +993,6 @@ def _rename(
         index: Renamer | None = None,
         columns: Renamer | None = None,
         axis: Axis | None = None,
-        copy: bool | None = None,
         inplace: bool = False,
         level: Level | None = None,
         errors: str = "ignore",
@@ -1061,7 +1063,7 @@ def rename_axis(
         index=...,
         columns=...,
         axis: Axis = ...,
-        copy: bool | None = ...,
+        copy: bool | lib.NoDefault = lib.no_default,
         inplace: Literal[False] = ...,
     ) -> Self: ...
 
@@ -1073,7 +1075,7 @@ def rename_axis(
         index=...,
         columns=...,
         axis: Axis = ...,
-        copy: bool | None = ...,
+        copy: bool | lib.NoDefault = lib.no_default,
         inplace: Literal[True],
     ) -> None: ...
 
@@ -1085,7 +1087,7 @@ def rename_axis(
         index=...,
         columns=...,
         axis: Axis = ...,
-        copy: bool | None = ...,
+        copy: bool | lib.NoDefault = lib.no_default,
         inplace: bool = ...,
     ) -> Self | None: ...
 
@@ -1096,7 +1098,7 @@ def rename_axis(
         index=lib.no_default,
         columns=lib.no_default,
         axis: Axis = 0,
-        copy: bool | None = None,
+        copy: bool | lib.NoDefault = lib.no_default,
         inplace: bool = False,
     ) -> Self | None:
         """
@@ -1118,7 +1120,7 @@ def rename_axis(
             apply to that axis' values.
         axis : {0 or 'index', 1 or 'columns'}, default 0
             The axis to rename.
-        copy : bool, default None
+        copy : bool, default False
             Also copy underlying data.
 
             .. note::
@@ -1132,6 +1134,8 @@ def rename_axis(
 
                 You can already get the future behavior and improvements through
                 enabling copy on write ``pd.options.mode.copy_on_write = True``
+
+            .. deprecated:: 3.0.0
         inplace : bool, default False
             Modifies the object directly, instead of creating a new Series
             or DataFrame.
@@ -1219,6 +1223,7 @@ class  name
                cat            4         0
                monkey         2         2
         """
+        self._check_copy_deprecation(copy)
         axes = {"index": index, "columns": columns}
 
         if axis is not None:
@@ -6327,7 +6332,7 @@ def astype(
             return self.copy(deep=False)
 
         # GH 19920: retain column metadata after concat
-        result = concat(results, axis=1, copy=False)
+        result = concat(results, axis=1)
         # GH#40810 retain subclass
         # error: Incompatible types in assignment
         # (expression has type "Self", variable has type "DataFrame")

pandas/core/interchange/dataframe.py

@@ -33,7 +33,7 @@ def __init__(self, df: DataFrame, allow_copy: bool = True) -> None:
         Constructor - an instance of this (private) class is returned from
         `pd.DataFrame.__dataframe__`.
         """
-        self._df = df.rename(columns=str, copy=False)
+        self._df = df.rename(columns=str)
         self._allow_copy = allow_copy
         for i, _col in enumerate(self._df.columns):
             rechunked = maybe_rechunk(self._df.iloc[:, i], allow_copy=allow_copy)