Merge branch 'master' into enh-bool-index

Author: jbrockmendel

doc/source/whatsnew/v1.4.0.rst

@@ -111,6 +111,7 @@ Additionally there are specific enhancements to the HTML specific rendering:
   - :meth:`.Styler.to_html` introduces keyword arguments ``sparse_index``, ``sparse_columns``, ``bold_headers``, ``caption``, ``max_rows`` and ``max_columns`` (:issue:`41946`, :issue:`43149`, :issue:`42972`).
   - :meth:`.Styler.to_html` omits CSSStyle rules for hidden table elements as a performance enhancement (:issue:`43619`)
   - Custom CSS classes can now be directly specified without string replacement (:issue:`43686`)
+  - Ability to render hyperlinks automatically via a new ``hyperlinks`` formatting keyword argument (:issue:`45058`)
 
 There are also some LaTeX specific enhancements:
 
@@ -364,10 +365,29 @@ second column is instead renamed to ``a.2``.
 
     res
 
-.. _whatsnew_140.notable_bug_fixes.notable_bug_fix3:
+.. _whatsnew_140.notable_bug_fixes.unstack_pivot_int32_limit:
 
-notable_bug_fix3
-^^^^^^^^^^^^^^^^
+unstack and pivot_table no longer raises ValueError for result that would exceed int32 limit
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Previously :meth:`DataFrame.pivot_table` and :meth:`DataFrame.unstack` would raise a ``ValueError`` if the operation
+could produce a result with more than ``2**31 - 1`` elements. This operation now raises a :class:`errors.PerformanceWarning`
+instead (:issue:`26314`).
+
+*Previous behavior*:
+
+.. code-block:: ipython
+
+    In [3]: df = DataFrame({"ind1": np.arange(2 ** 16), "ind2": np.arange(2 ** 16), "count": 0})
+    In [4]: df.pivot_table(index="ind1", columns="ind2", values="count", aggfunc="count")
+    ValueError: Unstacked DataFrame is too big, causing int32 overflow
+
+*New behavior*:
+
+.. code-block:: python
+
+    In [4]: df.pivot_table(index="ind1", columns="ind2", values="count", aggfunc="count")
+    PerformanceWarning: The following operation may generate 4294967296 cells in the resulting pandas object.
 
 .. ---------------------------------------------------------------------------
 
@@ -590,6 +610,7 @@ Other Deprecations
 - Deprecated :meth:`Index.__getitem__` with a bool key; use ``index.values[key]`` to get the old behavior (:issue:`44051`)
 - Deprecated downcasting column-by-column in :meth:`DataFrame.where` with integer-dtypes (:issue:`44597`)
 - Deprecated ``numeric_only=None`` in :meth:`DataFrame.rank`; in a future version ``numeric_only`` must be either ``True`` or ``False`` (the default) (:issue:`45036`)
+- Deprecated the behavior of :meth:`Timestamp.utcfromtimestamp`, in the future it will return a timezone-aware UTC :class:`Timestamp` (:issue:`22451`)
 - Deprecated :meth:`NaT.freq` (:issue:`45071`)
 -
 
@@ -682,6 +703,7 @@ Datetimelike
 - Bug in :meth:`Index.insert` for inserting ``np.datetime64``, ``np.timedelta64`` or ``tuple`` into :class:`Index` with ``dtype='object'`` with negative loc adding ``None`` and replacing existing value (:issue:`44509`)
 - Bug in :meth:`Series.mode` with ``DatetimeTZDtype`` incorrectly returning timezone-naive and ``PeriodDtype`` incorrectly raising (:issue:`41927`)
 - Bug in :class:`DateOffset`` addition with :class:`Timestamp` where ``offset.nanoseconds`` would not be included in the result (:issue:`43968`, :issue:`36589`)
+- Bug in :meth:`Timestamp.fromtimestamp` not supporting the ``tz`` argument (:issue:`45083`)
 -
 
 Timedelta

pandas/_libs/tslibs/nattype.pyx

@@ -378,9 +378,6 @@ class NaTType(_NaT):
     def __reduce__(self):
         return (__nat_unpickle, (None, ))
 
-    def __rdiv__(self, other):
-        return _nat_rdivide_op(self, other)
-
     def __rtruediv__(self, other):
         return _nat_rdivide_op(self, other)
 

pandas/_libs/tslibs/timestamps.pyx

@@ -1164,10 +1164,20 @@ class Timestamp(_Timestamp):
         >>> pd.Timestamp.utcfromtimestamp(1584199972)
         Timestamp('2020-03-14 15:32:52')
         """
+        # GH#22451
+        warnings.warn(
+            "The behavior of Timestamp.utcfromtimestamp is deprecated, in a "
+            "future version will return a timezone-aware Timestamp with UTC "
+            "timezone. To keep the old behavior, use "
+            "Timestamp.utcfromtimestamp(ts).tz_localize(None). "
+            "To get the future behavior, use Timestamp.fromtimestamp(ts, 'UTC')",
+            FutureWarning,
+            stacklevel=1,
+        )
         return cls(datetime.utcfromtimestamp(ts))
 
     @classmethod
-    def fromtimestamp(cls, ts):
+    def fromtimestamp(cls, ts, tz=None):
         """
         Timestamp.fromtimestamp(ts)
 
@@ -1180,7 +1190,8 @@ class Timestamp(_Timestamp):
 
         Note that the output may change depending on your local time.
         """
-        return cls(datetime.fromtimestamp(ts))
+        tz = maybe_get_tz(tz)
+        return cls(datetime.fromtimestamp(ts, tz))
 
     def strftime(self, format):
         """

pandas/core/algorithms.py

@@ -63,7 +63,10 @@
     needs_i8_conversion,
 )
 from pandas.core.dtypes.concat import concat_compat
-from pandas.core.dtypes.dtypes import PandasDtype
+from pandas.core.dtypes.dtypes import (
+    ExtensionDtype,
+    PandasDtype,
+)
 from pandas.core.dtypes.generic import (
     ABCDatetimeArray,
     ABCExtensionArray,
@@ -489,7 +492,7 @@ def isin(comps: AnyArrayLike, values: AnyArrayLike) -> npt.NDArray[np.bool_]:
     elif needs_i8_conversion(values.dtype):
         return isin(comps, values.astype(object))
 
-    elif is_extension_array_dtype(values.dtype):
+    elif isinstance(values.dtype, ExtensionDtype):
         return isin(np.asarray(comps), np.asarray(values))
 
     # GH16012
@@ -508,19 +511,7 @@ def f(c, v):
             f = np.in1d
 
     else:
-        # error: List item 0 has incompatible type "Union[Any, dtype[Any],
-        # ExtensionDtype]"; expected "Union[dtype[Any], None, type, _SupportsDType, str,
-        # Tuple[Any, Union[int, Sequence[int]]], List[Any], _DTypeDict, Tuple[Any,
-        # Any]]"
-        # error: List item 1 has incompatible type "Union[Any, ExtensionDtype]";
-        # expected "Union[dtype[Any], None, type, _SupportsDType, str, Tuple[Any,
-        # Union[int, Sequence[int]]], List[Any], _DTypeDict, Tuple[Any, Any]]"
-        # error: List item 1 has incompatible type "Union[dtype[Any], ExtensionDtype]";
-        # expected "Union[dtype[Any], None, type, _SupportsDType, str, Tuple[Any,
-        # Union[int, Sequence[int]]], List[Any], _DTypeDict, Tuple[Any, Any]]"
-        common = np.find_common_type(
-            [values.dtype, comps.dtype], []  # type: ignore[list-item]
-        )
+        common = np.find_common_type([values.dtype, comps.dtype], [])
         values = values.astype(common, copy=False)
         comps = comps.astype(common, copy=False)
         f = htable.ismember
@@ -932,7 +923,7 @@ def duplicated(
     return htable.duplicated(values, keep=keep)
 
 
-def mode(values, dropna: bool = True) -> Series:
+def mode(values: ArrayLike, dropna: bool = True) -> ArrayLike:
     """
     Returns the mode(s) of an array.
 
@@ -945,27 +936,17 @@ def mode(values, dropna: bool = True) -> Series:
 
     Returns
     -------
-    mode : Series
+    np.ndarray or ExtensionArray
     """
-    from pandas import Series
-    from pandas.core.indexes.api import default_index
-
     values = _ensure_arraylike(values)
     original = values
 
-    # categorical is a fast-path
-    if is_categorical_dtype(values.dtype):
-        if isinstance(values, Series):
-            # TODO: should we be passing `name` below?
-            return Series(values._values.mode(dropna=dropna), name=values.name)
-        return values.mode(dropna=dropna)
-
     if needs_i8_conversion(values.dtype):
-        if dropna:
-            mask = values.isna()
-            values = values[~mask]
-        modes = mode(values.view("i8"))
-        return modes.view(original.dtype)
+        # Got here with ndarray; dispatch to DatetimeArray/TimedeltaArray.
+        values = ensure_wrapped_if_datetimelike(values)
+        # error: Item "ndarray[Any, Any]" of "Union[ExtensionArray,
+        # ndarray[Any, Any]]" has no attribute "_mode"
+        return values._mode(dropna=dropna)  # type: ignore[union-attr]
 
     values = _ensure_data(values)
 
@@ -976,8 +957,7 @@ def mode(values, dropna: bool = True) -> Series:
         warn(f"Unable to sort modes: {err}")
 
     result = _reconstruct_data(npresult, original.dtype, original)
-    # Ensure index is type stable (should always use int index)
-    return Series(result, index=default_index(len(result)))
+    return result
 
 
 def rank(

pandas/core/arraylike.py

@@ -521,10 +521,12 @@ def dispatch_reduction_ufunc(self, ufunc: np.ufunc, method: str, *inputs, **kwar
 
         if "axis" not in kwargs:
             # For DataFrame reductions we don't want the default axis=0
-            # FIXME: DataFrame.min ignores axis=None
-            # FIXME: np.minimum.reduce(df) gets here bc axis is not in kwargs,
-            #  but np.minimum.reduce(df.values) behaves as if axis=0
-            kwargs["axis"] = None
+            # Note: np.min is not a ufunc, but uses array_function_dispatch,
+            #  so calls DataFrame.min (without ever getting here) with the np.min
+            #  default of axis=None, which DataFrame.min catches and changes to axis=0.
+            # np.minimum.reduce(df) gets here bc axis is not in kwargs,
+            #  so we set axis=0 to match the behaviorof np.minimum.reduce(df.values)
+            kwargs["axis"] = 0
 
     # By default, numpy's reductions do not skip NaNs, so we have to
     #  pass skipna=False

pandas/core/arrays/base.py

@@ -73,6 +73,7 @@
 from pandas.core.algorithms import (
     factorize_array,
     isin,
+    mode,
     rank,
     unique,
 )
@@ -1578,6 +1579,26 @@ def _quantile(
 
         return result
 
+    def _mode(self: ExtensionArrayT, dropna: bool = True) -> ExtensionArrayT:
+        """
+        Returns the mode(s) of the ExtensionArray.
+
+        Always returns `ExtensionArray` even if only one value.
+
+        Parameters
+        ----------
+        dropna : bool, default True
+            Don't consider counts of NA values.
+
+        Returns
+        -------
+        same type as self
+            Sorted, if possible.
+        """
+        # error: Incompatible return value type (got "Union[ExtensionArray,
+        # ndarray[Any, Any]]", expected "ExtensionArrayT")
+        return mode(self, dropna=dropna)  # type: ignore[return-value]
+
     def __array_ufunc__(self, ufunc: np.ufunc, method: str, *inputs, **kwargs):
         if any(
             isinstance(other, (ABCSeries, ABCIndex, ABCDataFrame)) for other in inputs

pandas/core/arrays/categorical.py

@@ -2229,7 +2229,7 @@ def max(self, *, skipna=True, **kwargs):
             pointer = self._codes.max()
         return self._wrap_reduction_result(None, pointer)
 
-    def mode(self, dropna=True):
+    def mode(self, dropna: bool = True) -> Categorical:
         """
         Returns the mode(s) of the Categorical.
 
@@ -2244,6 +2244,15 @@ def mode(self, dropna=True):
         -------
         modes : `Categorical` (sorted)
         """
+        warn(
+            "Categorical.mode is deprecated and will be removed in a future version. "
+            "Use Series.mode instead.",
+            FutureWarning,
+            stacklevel=find_stack_level(),
+        )
+        return self._mode(dropna=dropna)
+
+    def _mode(self, dropna: bool = True) -> Categorical:
         codes = self._codes
         if dropna:
             good = self._codes != -1

pandas/core/arrays/datetimelike.py

@@ -99,6 +99,7 @@
 from pandas.core.algorithms import (
     checked_add_with_arr,
     isin,
+    mode,
     unique1d,
 )
 from pandas.core.arraylike import OpsMixin
@@ -1531,6 +1532,17 @@ def median(self, *, axis: int | None = None, skipna: bool = True, **kwargs):
         result = nanops.nanmedian(self._ndarray, axis=axis, skipna=skipna)
         return self._wrap_reduction_result(axis, result)
 
+    def _mode(self, dropna: bool = True):
+        values = self
+        if dropna:
+            mask = values.isna()
+            values = values[~mask]
+
+        i8modes = mode(values.view("i8"))
+        npmodes = i8modes.view(self._ndarray.dtype)
+        npmodes = cast(np.ndarray, npmodes)
+        return self._from_backing_data(npmodes)
+
 
 class DatelikeOps(DatetimeLikeArrayMixin):
     """

pandas/core/arrays/floating.py

@@ -127,7 +127,7 @@ def coerce_to_array(
         return values, mask
 
     values = np.array(values, copy=copy)
-    if is_object_dtype(values):
+    if is_object_dtype(values.dtype):
         inferred_type = lib.infer_dtype(values, skipna=True)
         if inferred_type == "empty":
             pass

pandas/core/arrays/integer.py

@@ -177,7 +177,7 @@ def coerce_to_array(
 
     values = np.array(values, copy=copy)
     inferred_type = None
-    if is_object_dtype(values) or is_string_dtype(values):
+    if is_object_dtype(values.dtype) or is_string_dtype(values.dtype):
         inferred_type = lib.infer_dtype(values, skipna=True)
         if inferred_type == "empty":
             pass