From f8422aee070cc9fe5b9f57c9df0e2eeedf53dd52 Mon Sep 17 00:00:00 2001
From: Brock <jbrockmendel@gmail.com>
Date: Mon, 9 Oct 2023 17:55:18 -0700
Subject: [PATCH] DEPR: Series constructor fastpath keyword
---
asv_bench/benchmarks/series_methods.py | 3 ---
doc/source/whatsnew/v2.2.0.rst | 1 +
pandas/core/frame.py | 7 +------
pandas/core/series.py | 15 +++++++++++++--
pandas/tests/copy_view/test_constructors.py | 8 ++++++--
5 files changed, 21 insertions(+), 13 deletions(-)
diff --git a/asv_bench/benchmarks/series_methods.py b/asv_bench/benchmarks/series_methods.py
index 288369145576e..f52f7a4bef37a 100644
--- a/asv_bench/benchmarks/series_methods.py
+++ b/asv_bench/benchmarks/series_methods.py
@@ -28,9 +28,6 @@ def time_constructor_dict(self):
def time_constructor_no_data(self):
Series(data=None, index=self.idx)
- def time_constructor_fastpath(self):
- Series(self.array, index=self.idx2, name="name", fastpath=True)
-
class ToFrame:
params = [["int64", "datetime64[ns]", "category", "Int64"], [None, "foo"]]
diff --git a/doc/source/whatsnew/v2.2.0.rst b/doc/source/whatsnew/v2.2.0.rst
index cfcc99bf5bda0..09067d541d01b 100644
--- a/doc/source/whatsnew/v2.2.0.rst
+++ b/doc/source/whatsnew/v2.2.0.rst
@@ -256,6 +256,7 @@ Other Deprecations
- Deprecated strings ``H``, ``S``, ``U``, and ``N`` denoting units in :func:`to_timedelta` (:issue:`52536`)
- Deprecated strings ``H``, ``T``, ``S``, ``L``, ``U``, and ``N`` denoting units in :class:`Timedelta` (:issue:`52536`)
- Deprecated strings ``T``, ``S``, ``L``, ``U``, and ``N`` denoting frequencies in :class:`Minute`, :class:`Second`, :class:`Milli`, :class:`Micro`, :class:`Nano` (:issue:`52536`)
+- Deprecated the ``fastpath`` keyword in the :class:`Series` constructor (:issue:`20110`)
- Deprecated the extension test classes ``BaseNoReduceTests``, ``BaseBooleanReduceTests``, and ``BaseNumericReduceTests``, use ``BaseReduceTests`` instead (:issue:`54663`)
- Deprecated the option ``mode.data_manager`` and the ``ArrayManager``; only the ``BlockManager`` will be available in future versions (:issue:`55043`)
- Deprecating downcasting the results of :meth:`DataFrame.fillna`, :meth:`Series.fillna`, :meth:`DataFrame.ffill`, :meth:`Series.ffill`, :meth:`DataFrame.bfill`, :meth:`Series.bfill` in object-dtype cases. To opt in to the future version, use ``pd.set_option("future.no_silent_downcasting", True)`` (:issue:`54261`)
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index 7802657269044..09c43822e11e4 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -5168,12 +5168,7 @@ def _sanitize_column(self, value) -> tuple[ArrayLike, BlockValuesRefs | None]:
@property
def _series(self):
- return {
- item: Series(
- self._mgr.iget(idx), index=self.index, name=item, fastpath=True
- )
- for idx, item in enumerate(self.columns)
- }
+ return {item: self._ixs(idx, axis=1) for idx, item in enumerate(self.columns)}
# ----------------------------------------------------------------------
# Reindexing and alignment
diff --git a/pandas/core/series.py b/pandas/core/series.py
index ae9f77a6c0bad..c2eea371ddef3 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -374,8 +374,18 @@ def __init__(
dtype: Dtype | None = None,
name=None,
copy: bool | None = None,
- fastpath: bool = False,
+ fastpath: bool | lib.NoDefault = lib.no_default,
) -> None:
+ if fastpath is not lib.no_default:
+ warnings.warn(
+ "The 'fastpath' keyword in pd.Series is deprecated and will "
+ "be removed in a future version.",
+ DeprecationWarning,
+ stacklevel=find_stack_level(),
+ )
+ else:
+ fastpath = False
+
if (
isinstance(data, (SingleBlockManager, SingleArrayManager))
and index is None
@@ -1009,7 +1019,8 @@ def _slice(self, slobj: slice, axis: AxisInt = 0) -> Series:
# axis kwarg is retained for compat with NDFrame method
# _slice is *always* positional
mgr = self._mgr.get_slice(slobj, axis=axis)
- out = self._constructor(mgr, fastpath=True)
+ out = self._constructor_from_mgr(mgr, axes=mgr.axes)
+ out._name = self._name
return out.__finalize__(self)
def __getitem__(self, key):
diff --git a/pandas/tests/copy_view/test_constructors.py b/pandas/tests/copy_view/test_constructors.py
index af7e759902f9f..31f80d300ccca 100644
--- a/pandas/tests/copy_view/test_constructors.py
+++ b/pandas/tests/copy_view/test_constructors.py
@@ -99,7 +99,9 @@ def test_series_from_series_with_reindex(using_copy_on_write):
def test_series_from_array(using_copy_on_write, idx, dtype, fastpath, arr):
if idx is None or dtype is not None:
fastpath = False
- ser = Series(arr, dtype=dtype, index=idx, fastpath=fastpath)
+ msg = "The 'fastpath' keyword in pd.Series is deprecated"
+ with tm.assert_produces_warning(DeprecationWarning, match=msg):
+ ser = Series(arr, dtype=dtype, index=idx, fastpath=fastpath)
ser_orig = ser.copy()
data = getattr(arr, "_data", arr)
if using_copy_on_write:
@@ -157,7 +159,9 @@ def test_series_from_index_different_dtypes(using_copy_on_write):
def test_series_from_block_manager(using_copy_on_write, idx, dtype, fastpath):
ser = Series([1, 2, 3], dtype="int64")
ser_orig = ser.copy()
- ser2 = Series(ser._mgr, dtype=dtype, fastpath=fastpath, index=idx)
+ msg = "The 'fastpath' keyword in pd.Series is deprecated"
+ with tm.assert_produces_warning(DeprecationWarning, match=msg):
+ ser2 = Series(ser._mgr, dtype=dtype, fastpath=fastpath, index=idx)
assert np.shares_memory(get_array(ser), get_array(ser2))
if using_copy_on_write:
assert not ser2._mgr._has_no_reference(0)