Merge branch 'main' into shiny-new-feature

Author: Chiwendaiyue

README.md

@@ -179,7 +179,7 @@ If you are simply looking to start working with the pandas codebase, navigate to
 
 You can also triage issues which may include reproducing bug reports, or asking for vital information such as version numbers or reproduction instructions. If you would like to start triaging issues, one easy way to get started is to [subscribe to pandas on CodeTriage](https://www.codetriage.com/pandas-dev/pandas).
 
-Or maybe through using pandas you have an idea of your own or are looking for something in the documentation and thinking ‘this can be improved’...you can do something about it!
+Or maybe through using pandas you have an idea of your own or are looking for something in the documentation and thinking ‘this can be improved’... you can do something about it!
 
 Feel free to ask questions on the [mailing list](https://groups.google.com/forum/?fromgroups#!forum/pydata) or on [Slack](https://pandas.pydata.org/docs/dev/development/community.html?highlight=slack#community-slack).
 

doc/make.py

@@ -105,7 +105,7 @@ def _process_single_doc(self, single_doc):
     @staticmethod
     def _run_os(*args) -> None:
         """
-        Execute a command as a OS terminal.
+        Execute a command as an OS terminal.
 
         Parameters
         ----------

doc/source/whatsnew/v3.0.0.rst

@@ -738,6 +738,7 @@ Other Deprecations
 - Deprecated allowing ``fill_value`` that cannot be held in the original dtype (excepting NA values for integer and bool dtypes) in :meth:`Series.shift` and :meth:`DataFrame.shift` (:issue:`53802`)
 - Deprecated backward-compatibility behavior for :meth:`DataFrame.select_dtypes` matching "str" dtype when ``np.object_`` is specified (:issue:`61916`)
 - Deprecated option "future.no_silent_downcasting", as it is no longer used. In a future version accessing this option will raise (:issue:`59502`)
+- Deprecated silent casting of non-datetime 'other' to datetime in :meth:`Series.combine_first` (:issue:`62931`)
 - Deprecated slicing on a :class:`Series` or :class:`DataFrame` with a :class:`DatetimeIndex` using a ``datetime.date`` object, explicitly cast to :class:`Timestamp` instead (:issue:`35830`)
 - Deprecated the 'inplace' keyword from :meth:`Resampler.interpolate`, as passing ``True`` raises ``AttributeError`` (:issue:`58690`)
 
@@ -975,12 +976,15 @@ Datetimelike
 - Bug in :class:`Timestamp` constructor failing to raise when given a ``np.datetime64`` object with non-standard unit (:issue:`25611`)
 - Bug in :func:`date_range` where the last valid timestamp would sometimes not be produced (:issue:`56134`)
 - Bug in :func:`date_range` where using a negative frequency value would not include all points between the start and end values (:issue:`56147`)
+- Bug in :func:`infer_freq` with a :class:`Series` with :class:`ArrowDtype` timestamp dtype incorrectly raising ``TypeError`` (:issue:`58403`)
 - Bug in :func:`to_datetime` where passing an ``lxml.etree._ElementUnicodeResult`` together with ``format`` raised  ``TypeError``. Now subclasses of ``str`` are handled. (:issue:`60933`)
 - Bug in :func:`tseries.api.guess_datetime_format` would fail to infer time format when "%Y" == "%H%M" (:issue:`57452`)
 - Bug in :func:`tseries.frequencies.to_offset` would fail to parse frequency strings starting with "LWOM" (:issue:`59218`)
 - Bug in :meth:`DataFrame.fillna` raising an ``AssertionError`` instead of ``OutOfBoundsDatetime`` when filling a ``datetime64[ns]`` column with an out-of-bounds timestamp. Now correctly raises ``OutOfBoundsDatetime``. (:issue:`61208`)
 - Bug in :meth:`DataFrame.min` and :meth:`DataFrame.max` casting ``datetime64`` and ``timedelta64`` columns to ``float64`` and losing precision (:issue:`60850`)
 - Bug in :meth:`Dataframe.agg` with df with missing values resulting in IndexError (:issue:`58810`)
+- Bug in :meth:`DateOffset.rollback` (and subclass methods) with ``normalize=True`` rolling back one offset too long (:issue:`32616`)
+- Bug in :meth:`DatetimeIndex.asof` with a string key giving incorrect results (:issue:`50946`)
 - Bug in :meth:`DatetimeIndex.is_year_start` and :meth:`DatetimeIndex.is_quarter_start` does not raise on Custom business days frequencies bigger then "1C" (:issue:`58664`)
 - Bug in :meth:`DatetimeIndex.is_year_start` and :meth:`DatetimeIndex.is_quarter_start` returning ``False`` on double-digit frequencies (:issue:`58523`)
 - Bug in :meth:`DatetimeIndex.union` and :meth:`DatetimeIndex.intersection` when ``unit`` was non-nanosecond (:issue:`59036`)
@@ -999,6 +1003,7 @@ Datetimelike
 - Bug in comparison between objects with pyarrow date dtype and ``timestamp[pyarrow]`` or ``np.datetime64`` dtype failing to consider these as non-comparable (:issue:`62157`)
 - Bug in constructing arrays with :class:`ArrowDtype` with ``timestamp`` type incorrectly allowing ``Decimal("NaN")`` (:issue:`61773`)
 - Bug in constructing arrays with a timezone-aware :class:`ArrowDtype` from timezone-naive datetime objects incorrectly treating those as UTC times instead of wall times like :class:`DatetimeTZDtype` (:issue:`61775`)
+- Bug in retaining frequency in :meth:`value_counts` specifically for :meth:`DatetimeIndex` and :meth:`TimedeltaIndex` (:issue:`33830`)
 - Bug in setting scalar values with mismatched resolution into arrays with non-nanosecond ``datetime64``, ``timedelta64`` or :class:`DatetimeTZDtype` incorrectly truncating those scalars (:issue:`56410`)
 
 Timedelta
@@ -1050,6 +1055,7 @@ Interval
 - Bug in :class:`Index`, :class:`Series`, :class:`DataFrame` constructors when given a sequence of :class:`Interval` subclass objects casting them to :class:`Interval` (:issue:`46945`)
 - Bug in :func:`interval_range` where start and end numeric types were always cast to 64 bit (:issue:`57268`)
 - Bug in :meth:`IntervalIndex.get_indexer` and :meth:`IntervalIndex.drop` when one of the sides of the index is non-unique (:issue:`52245`)
+- Construction of :class:`IntervalArray` and :class:`IntervalIndex` from arrays with mismatched signed/unsigned integer dtypes (e.g., ``int64`` and ``uint64``) now raises a :exc:`TypeError` instead of proceeding silently. (:issue:`55715`)
 
 Indexing
 ^^^^^^^^
@@ -1181,10 +1187,13 @@ Reshaping
 - Bug in :func:`concat` with mixed integer and bool dtypes incorrectly casting the bools to integers (:issue:`45101`)
 - Bug in :func:`qcut` where values at the quantile boundaries could be incorrectly assigned (:issue:`59355`)
 - Bug in :meth:`DataFrame.combine_first` not preserving the column order (:issue:`60427`)
+- Bug in :meth:`DataFrame.combine_first` with non-unique columns incorrectly raising (:issue:`29135`)
+- Bug in :meth:`DataFrame.combine` with non-unique columns incorrectly raising (:issue:`51340`)
 - Bug in :meth:`DataFrame.explode` producing incorrect result for :class:`pyarrow.large_list` type (:issue:`61091`)
 - Bug in :meth:`DataFrame.join` inconsistently setting result index name (:issue:`55815`)
 - Bug in :meth:`DataFrame.join` when a :class:`DataFrame` with a :class:`MultiIndex` would raise an ``AssertionError`` when :attr:`MultiIndex.names` contained ``None``. (:issue:`58721`)
 - Bug in :meth:`DataFrame.merge` where merging on a column containing only ``NaN`` values resulted in an out-of-bounds array access (:issue:`59421`)
+- Bug in :meth:`Series.combine_first` incorrectly replacing ``None`` entries with ``NaN`` (:issue:`58977`)
 - Bug in :meth:`DataFrame.unstack` producing incorrect results when ``sort=False`` (:issue:`54987`, :issue:`55516`)
 - Bug in :meth:`DataFrame.unstack` raising an error with indexes containing ``NaN`` with ``sort=False`` (:issue:`61221`)
 - Bug in :meth:`DataFrame.merge` when merging two :class:`DataFrame` on ``intc`` or ``uintc`` types on Windows (:issue:`60091`, :issue:`58713`)
@@ -1237,6 +1246,7 @@ Other
 - Bug in :meth:`DataFrame.query` where using duplicate column names led to a ``TypeError``. (:issue:`59950`)
 - Bug in :meth:`DataFrame.query` which raised an exception or produced incorrect results when expressions contained backtick-quoted column names containing the hash character ``#``, backticks, or characters that fall outside the ASCII range (U+0001..U+007F). (:issue:`59285`) (:issue:`49633`)
 - Bug in :meth:`DataFrame.query` which raised an exception when querying integer column names using backticks. (:issue:`60494`)
+- Bug in :meth:`DataFrame.rename` and :meth:`Series.rename` when passed a ``mapper``, ``index``, or ``columns`` argument that is a :class:`Series` with non-unique ``ser.index`` producing a corrupted result instead of raising ``ValueError`` (:issue:`58621`)
 - Bug in :meth:`DataFrame.sample` with ``replace=False`` and ``(n * max(weights) / sum(weights)) > 1``, the method would return biased results. Now raises ``ValueError``. (:issue:`61516`)
 - Bug in :meth:`DataFrame.shift` where passing a ``freq`` on a DataFrame with no columns did not shift the index correctly. (:issue:`60102`)
 - Bug in :meth:`DataFrame.sort_index` when passing ``axis="columns"`` and ``ignore_index=True`` and ``ascending=False`` not returning a :class:`RangeIndex` columns (:issue:`57293`)

pandas/_config/localization.py

@@ -79,7 +79,7 @@ def can_set_locale(lc: str, lc_var: int = locale.LC_ALL) -> bool:
         with set_locale(lc, lc_var=lc_var):
             pass
     except (ValueError, locale.Error):
-        # horrible name for a Exception subclass
+        # horrible name for an Exception subclass
         return False
     else:
         return True

pandas/_libs/tslibs/offsets.pyx

@@ -692,6 +692,9 @@ cdef class BaseOffset:
             Rolled timestamp if not on offset, otherwise unchanged timestamp.
         """
         dt = Timestamp(dt)
+        if self.normalize and (dt - dt.normalize())._value != 0:
+            # GH#32616
+            dt = dt.normalize()
         if not self.is_on_offset(dt):
             dt = dt - type(self)(1, normalize=self.normalize, **self.kwds)
         return dt

pandas/core/algorithms.py

@@ -868,8 +868,10 @@ def value_counts_internal(
     dropna: bool = True,
 ) -> Series:
     from pandas import (
+        DatetimeIndex,
         Index,
         Series,
+        TimedeltaIndex,
     )
 
     index_name = getattr(values, "name", None)
@@ -934,6 +936,17 @@ def value_counts_internal(
             # Starting in 3.0, we no longer perform dtype inference on the
             #  Index object we construct here, xref GH#56161
             idx = Index(keys, dtype=keys.dtype, name=index_name)
+
+            if (
+                bins is None
+                and not sort
+                and isinstance(values, (DatetimeIndex, TimedeltaIndex))
+                and idx.equals(values)
+                and values.inferred_freq is not None
+            ):
+                # Preserve freq of original index
+                idx.freq = values.inferred_freq  # type: ignore[attr-defined]
+
             result = Series(counts, index=idx, name=name, copy=False)
 
     if sort:

pandas/core/arrays/arrow/array.py

@@ -829,6 +829,14 @@ def __arrow_array__(self, type=None):
         """Convert myself to a pyarrow ChunkedArray."""
         return self._pa_array
 
+    def __array_ufunc__(self, ufunc: np.ufunc, method: str, *inputs, **kwargs):
+        # Need to wrap np.array results GH#62800
+        result = super().__array_ufunc__(ufunc, method, *inputs, **kwargs)
+        if type(self) is ArrowExtensionArray:
+            # Exclude ArrowStringArray
+            return type(self)._from_sequence(result)
+        return result
+
     def __array__(
         self, dtype: NpDtype | None = None, copy: bool | None = None
     ) -> np.ndarray:

pandas/core/arrays/categorical.py

@@ -269,7 +269,7 @@ class Categorical(NDArrayBackedExtensionArray, PandasObject, ObjectStringArrayMi
         categories are assumed to be the unique values of `values` (sorted, if
         possible, otherwise in the order in which they appear).
     ordered : bool, default False
-        Whether or not this categorical is treated as a ordered categorical.
+        Whether or not this categorical is treated as an ordered categorical.
         If True, the resulting categorical will be ordered.
         An ordered categorical respects, when sorted, the order of its
         `categories` attribute (which in turn is the `categories` argument, if
@@ -1103,7 +1103,7 @@ def set_categories(
         new_categories : Index-like
            The categories in new order.
         ordered : bool, default None
-           Whether or not the categorical is treated as a ordered categorical.
+           Whether or not the categorical is treated as an ordered categorical.
            If not given, do not change the ordered information.
         rename : bool, default False
            Whether or not the new_categories should be considered as a rename
@@ -1277,7 +1277,7 @@ def reorder_categories(self, new_categories, ordered=None) -> Self:
         new_categories : Index-like
            The categories in new order.
         ordered : bool, optional
-           Whether or not the categorical is treated as a ordered categorical.
+           Whether or not the categorical is treated as an ordered categorical.
            If not given, do not change the ordered information.
 
         Returns

pandas/core/arrays/interval.py

@@ -420,6 +420,18 @@ def _ensure_simple_new_inputs(
 
         dtype = IntervalDtype(left.dtype, closed=closed)
 
+        # Check for mismatched signed/unsigned integer dtypes after casting
+        left_dtype = left.dtype
+        right_dtype = right.dtype
+        if (
+            left_dtype.kind in "iu"
+            and right_dtype.kind in "iu"
+            and left_dtype.kind != right_dtype.kind
+        ):
+            raise TypeError(
+                f"Left and right arrays must have matching signedness. "
+                f"Got {left_dtype} and {right_dtype}."
+            )
         return left, right, dtype
 
     @classmethod

pandas/core/arrays/timedeltas.py

@@ -1212,7 +1212,7 @@ def _objects_to_td64ns(
     data, unit=None, errors: DateTimeErrorChoices = "raise"
 ) -> np.ndarray:
     """
-    Convert a object-dtyped or string-dtyped array into an
+    Convert an object-dtyped or string-dtyped array into a
     timedelta64[ns]-dtyped array.
 
     Parameters