API: Deprecate renamae_axis and reindex_axis (pandas-dev#17842)

* API: Deprecate renamae_axis and reindex_axis

Closes pandas-dev#17833

* REF: Refactor axis style validator to generic

This sets us up to re-use it for Panel reindex

* fixup! API: Deprecate renamae_axis and reindex_axis

* fixup! API: Deprecate renamae_axis and reindex_axis

* fixup! API: Deprecate renamae_axis and reindex_axis

* fixup! API: Deprecate renamae_axis and reindex_axis

* Ugh

* fixup! API: Deprecate renamae_axis and reindex_axis

* Fixup

doc/source/basics.rst

@@ -1201,8 +1201,11 @@ With a DataFrame, you can simultaneously reindex the index and columns:
    df
    df.reindex(index=['c', 'f', 'b'], columns=['three', 'two', 'one'])
 
-For convenience, you may utilize the :meth:`~Series.reindex_axis` method, which
-takes the labels and a keyword ``axis`` parameter.
+You may also use ``reindex`` with an ``axis`` keyword:
+
+.. ipython:: python
+
+   df.reindex(index=['c', 'f', 'b'], axis='index')
 
 Note that the ``Index`` objects containing the actual axis labels can be
 **shared** between objects. So if we have a Series and a DataFrame, the

doc/source/whatsnew/v0.21.0.txt

@@ -810,6 +810,8 @@ Deprecations
 - ``.get_value`` and ``.set_value`` on ``Series``, ``DataFrame``, ``Panel``, ``SparseSeries``, and ``SparseDataFrame`` are deprecated in favor of using ``.iat[]`` or ``.at[]`` accessors (:issue:`15269`)
 - Passing a non-existent column in ``.to_excel(..., columns=)`` is deprecated and will raise a ``KeyError`` in the future (:issue:`17295`)
 - ``raise_on_error`` parameter to :func:`Series.where`, :func:`Series.mask`, :func:`DataFrame.where`, :func:`DataFrame.mask` is deprecated, in favor of ``errors=`` (:issue:`14968`)
+- Using :meth:`DataFrame.rename_axis` and :meth:`Series.rename_axis` to alter index or column *labels* is now deprecated in favor of using ``.rename``. ``rename_axis`` may still be used to alter the name of the index or columns (:issue:`17833`).
+- :meth:`~DataFrame.reindex_axis` has been deprecated in favor of :meth:`~DataFrame.reindex`. See :ref`here` <whatsnew_0210.enhancements.rename_reindex_axis> for more (:issue:`17833`).
 
 .. _whatsnew_0210.deprecations.select:
 
@@ -998,6 +1000,7 @@ Reshaping
 - Bug in :func:`unique` where checking a tuple of strings raised a ``TypeError`` (:issue:`17108`)
 - Bug in :func:`concat` where order of result index was unpredictable if it contained non-comparable elements (:issue:`17344`)
 - Fixes regression when sorting by multiple columns on a ``datetime64`` dtype ``Series`` with ``NaT`` values (:issue:`16836`)
+- Bug in :fun:`pivot_table` where the result's columns did not preserve the categorical dtype of ``columns`` when ``dropna`` was ``False`` (:issue:`17842`)
 
 Numeric
 ^^^^^^^

pandas/core/computation/align.py

@@ -89,7 +89,7 @@ def _align_core(terms):
         for axis, items in zip(range(ndim), axes):
             ti = terms[i].value
 
-            if hasattr(ti, 'reindex_axis'):
+            if hasattr(ti, 'reindex'):
                 transpose = isinstance(ti, pd.Series) and naxes > 1
                 reindexer = axes[naxes - 1] if transpose else items
 
@@ -104,11 +104,7 @@ def _align_core(terms):
                          ).format(axis=axis, term=terms[i].name, ordm=ordm)
                     warnings.warn(w, category=PerformanceWarning, stacklevel=6)
 
-                if transpose:
-                    f = partial(ti.reindex, index=reindexer, copy=False)
-                else:
-                    f = partial(ti.reindex_axis, reindexer, axis=axis,
-                                copy=False)
+                f = partial(ti.reindex, reindexer, axis=axis, copy=False)
 
                 terms[i].update(f())
 

pandas/core/frame.py

@@ -65,7 +65,6 @@
                                 _values_from_object,
                                 _maybe_box_datetimelike,
                                 _dict_compat,
-                                _all_not_none,
                                 standardize_mapping)
 from pandas.core.generic import NDFrame, _shared_docs
 from pandas.core.index import (Index, MultiIndex, _ensure_index,
@@ -2736,7 +2735,7 @@ def reindexer(value):
                 if isinstance(loc, (slice, Series, np.ndarray, Index)):
                     cols = maybe_droplevels(self.columns[loc], key)
                     if len(cols) and not cols.equals(value.columns):
-                        value = value.reindex_axis(cols, axis=1)
+                        value = value.reindex(cols, axis=1)
             # now align rows
             value = reindexer(value).T
 
@@ -2783,47 +2782,6 @@ def reindexer(value):
 
         return np.atleast_2d(np.asarray(value))
 
-    def _validate_axis_style_args(self, arg, arg_name, index, columns,
-                                  axis, method_name):
-        if axis is not None:
-            # Using "axis" style, along with a positional arg
-            # Both index and columns should be None then
-            axis = self._get_axis_name(axis)
-            if index is not None or columns is not None:
-                msg = (
-                    "Can't specify both 'axis' and 'index' or 'columns'. "
-                    "Specify either\n"
-                    "\t.{method_name}.rename({arg_name}, axis=axis), or\n"
-                    "\t.{method_name}.rename(index=index, columns=columns)"
-                ).format(arg_name=arg_name, method_name=method_name)
-                raise TypeError(msg)
-            if axis == 'index':
-                index = arg
-            elif axis == 'columns':
-                columns = arg
-
-        elif _all_not_none(arg, index, columns):
-            msg = (
-                "Cannot specify all of '{arg_name}', 'index', and 'columns'. "
-                "Specify either {arg_name} and 'axis', or 'index' and "
-                "'columns'."
-            ).format(arg_name=arg_name)
-            raise TypeError(msg)
-
-        elif _all_not_none(arg, index):
-            # This is the "ambiguous" case, so emit a warning
-            msg = (
-                "Interpreting call to '.{method_name}(a, b)' as "
-                "'.{method_name}(index=a, columns=b)'. "
-                "Use keyword arguments to remove any ambiguity."
-            ).format(method_name=method_name)
-            warnings.warn(msg, stacklevel=3)
-            index, columns = arg, index
-        elif index is None:
-            # This is for the default axis, like reindex([0, 1])
-            index = arg
-        return index, columns
-
     @property
     def _series(self):
         result = {}
@@ -2952,11 +2910,11 @@ def align(self, other, join='outer', axis=None, level=None, copy=True,
     @Appender(_shared_docs['reindex'] % _shared_doc_kwargs)
     def reindex(self, labels=None, index=None, columns=None, axis=None,
                 **kwargs):
-        index, columns = self._validate_axis_style_args(labels, 'labels',
-                                                        index, columns,
-                                                        axis, 'reindex')
-        return super(DataFrame, self).reindex(index=index, columns=columns,
-                                              **kwargs)
+        axes = self._validate_axis_style_args(labels, 'labels',
+                                              axes=[index, columns],
+                                              axis=axis, method_name='reindex')
+        kwargs.update(axes)
+        return super(DataFrame, self).reindex(**kwargs)
 
     @Appender(_shared_docs['reindex_axis'] % _shared_doc_kwargs)
     def reindex_axis(self, labels, axis=0, method=None, level=None, copy=True,
@@ -3041,11 +2999,11 @@ def rename(self, mapper=None, index=None, columns=None, axis=None,
         2  2  5
         4  3  6
         """
-        index, columns = self._validate_axis_style_args(mapper, 'mapper',
-                                                        index, columns,
-                                                        axis, 'rename')
-        return super(DataFrame, self).rename(index=index, columns=columns,
-                                             **kwargs)
+        axes = self._validate_axis_style_args(mapper, 'mapper',
+                                              axes=[index, columns],
+                                              axis=axis, method_name='rename')
+        kwargs.update(axes)
+        return super(DataFrame, self).rename(**kwargs)
 
     @Appender(_shared_docs['fillna'] % _shared_doc_kwargs)
     def fillna(self, value=None, method=None, axis=None, inplace=False,

pandas/core/generic.py

@@ -29,7 +29,8 @@
 from pandas.core.dtypes.missing import isna, notna
 from pandas.core.dtypes.generic import ABCSeries, ABCPanel, ABCDataFrame
 
-from pandas.core.common import (_values_from_object,
+from pandas.core.common import (_all_not_none,
+                                _values_from_object,
                                 _maybe_box_datetimelike,
                                 SettingWithCopyError, SettingWithCopyWarning,
                                 AbstractMethodError)
@@ -729,6 +730,51 @@ def swaplevel(self, i=-2, j=-1, axis=0):
         result._data.set_axis(axis, labels.swaplevel(i, j))
         return result
 
+    def _validate_axis_style_args(self, arg, arg_name, axes,
+                                  axis, method_name):
+        out = {}
+        for i, value in enumerate(axes):
+            if value is not None:
+                out[self._AXIS_NAMES[i]] = value
+
+        aliases = ', '.join(self._AXIS_NAMES.values())
+        if axis is not None:
+            # Using "axis" style, along with a positional arg
+            # Both index and columns should be None then
+            axis = self._get_axis_name(axis)
+            if any(x is not None for x in axes):
+                msg = (
+                    "Can't specify both 'axis' and {aliases}. "
+                    "Specify either\n"
+                    "\t.{method_name}({arg_name}, axis=axis), or\n"
+                    "\t.{method_name}(index=index, columns=columns)"
+                ).format(arg_name=arg_name, method_name=method_name,
+                         aliases=aliases)
+                raise TypeError(msg)
+            out[axis] = arg
+
+        elif _all_not_none(arg, *axes):
+            msg = (
+                "Cannot specify all of '{arg_name}', {aliases}. "
+                "Specify either {arg_name} and 'axis', or {aliases}."
+            ).format(arg_name=arg_name, aliases=aliases)
+            raise TypeError(msg)
+
+        elif _all_not_none(arg, axes[0]):
+            # This is the "ambiguous" case, so emit a warning
+            msg = (
+                "Interpreting call to '.{method_name}(a, b)' as "
+                "'.{method_name}(index=a, columns=b)'. "  # TODO
+                "Use keyword arguments to remove any ambiguity."
+            ).format(method_name=method_name)
+            warnings.warn(msg, stacklevel=3)
+            out[self._AXIS_ORDERS[0]] = arg
+            out[self._AXIS_ORDERS[1]] = axes[0]
+        elif axes[0] is None:
+            # This is for the default axis, like reindex([0, 1])
+            out[self._AXIS_ORDERS[0]] = arg
+        return out
+
     # ----------------------------------------------------------------------
     # Rename
 
@@ -893,17 +939,12 @@ def f(x):
     rename.__doc__ = _shared_docs['rename']
 
     def rename_axis(self, mapper, axis=0, copy=True, inplace=False):
-        """
-        Alter index and / or columns using input function or functions.
-        A scalar or list-like for ``mapper`` will alter the ``Index.name``
-        or ``MultiIndex.names`` attribute.
-        A function or dict for ``mapper`` will alter the labels.
-        Function / dict values must be unique (1-to-1). Labels not contained in
-        a dict / Series will be left as-is.
+        """Alter the name of the index or columns.
 
         Parameters
         ----------
-        mapper : scalar, list-like, dict-like or function, optional
+        mapper : scalar, list-like, optional
+            Value to set the axis name attribute.
         axis : int or string, default 0
         copy : boolean, default True
             Also copy underlying data
@@ -913,38 +954,45 @@ def rename_axis(self, mapper, axis=0, copy=True, inplace=False):
         -------
         renamed : type of caller or None if inplace=True
 
+        Notes
+        -----
+        Prior to version 0.21.0, ``rename_axis`` could also be used to change
+        the axis *labels* by passing a mapping or scalar. This behavior is
+        deprecated and will be removed in a future version. Use ``rename``
+        instead.
+
         See Also
         --------
-        pandas.NDFrame.rename
+        pandas.Series.rename, pandas.DataFrame.rename
         pandas.Index.rename
 
         Examples
         --------
 
         >>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
-        >>> df.rename_axis("foo")  # scalar, alters df.index.name
+        >>> df.rename_axis("foo")
              A  B
         foo
         0    1  4
         1    2  5
         2    3  6
-        >>> df.rename_axis(lambda x: 2 * x)  # function: alters labels
-           A  B
-        0  1  4
-        2  2  5
-        4  3  6
-        >>> df.rename_axis({"A": "ehh", "C": "see"}, axis="columns")  # mapping
-           ehh  B
+
+        >>> df.rename_axis("bar", axis="columns")
+        bar  A  B
         0    1  4
         1    2  5
         2    3  6
+
         """
         inplace = validate_bool_kwarg(inplace, 'inplace')
         non_mapper = is_scalar(mapper) or (is_list_like(mapper) and not
                                            is_dict_like(mapper))
         if non_mapper:
             return self._set_axis_name(mapper, axis=axis, inplace=inplace)
         else:
+            msg = ("Using 'rename_axis' to alter labels is deprecated. "
+                   "Use '.rename' instead")
+            warnings.warn(msg, FutureWarning, stacklevel=2)
             axis = self._get_axis_name(axis)
             d = {'copy': copy, 'inplace': inplace}
             d[axis] = mapper
@@ -2981,6 +3029,11 @@ def reindex(self, *args, **kwargs):
         tolerance = kwargs.pop('tolerance', None)
         fill_value = kwargs.pop('fill_value', np.nan)
 
+        # Series.reindex doesn't use / need the axis kwarg
+        # We pop and ignore it here, to make writing Series/Frame generic code
+        # easier
+        kwargs.pop("axis", None)
+
         if kwargs:
             raise TypeError('reindex() got an unexpected keyword '
                             'argument "{0}"'.format(list(kwargs.keys())[0]))
@@ -3085,11 +3138,14 @@ def _reindex_multi(self, axes, copy, fill_value):
     @Appender(_shared_docs['reindex_axis'] % _shared_doc_kwargs)
     def reindex_axis(self, labels, axis=0, method=None, level=None, copy=True,
                      limit=None, fill_value=np.nan):
+        msg = ("'.reindex_axis' is deprecated and will be removed in a future "
+               "version. Use '.reindex' instead.")
         self._consolidate_inplace()
 
         axis_name = self._get_axis_name(axis)
         axis_values = self._get_axis(axis_name)
         method = missing.clean_reindex_fill_method(method)
+        warnings.warn(msg, FutureWarning, stacklevel=3)
         new_index, indexer = axis_values.reindex(labels, method, level,
                                                  limit=limit)
         return self._reindex_with_indexers({axis: [new_index, indexer]},

pandas/core/groupby.py

@@ -901,7 +901,7 @@ def reset_identity(values):
                         result.index.get_indexer_for(ax.values))
                     result = result.take(indexer, axis=self.axis)
                 else:
-                    result = result.reindex_axis(ax, axis=self.axis)
+                    result = result.reindex(ax, axis=self.axis)
 
         elif self.group_keys:
 

pandas/core/indexing.py

@@ -368,7 +368,7 @@ def _setitem_with_indexer(self, indexer, value):
                     # so the object is the same
                     index = self.obj._get_axis(i)
                     labels = index.insert(len(index), key)
-                    self.obj._data = self.obj.reindex_axis(labels, i)._data
+                    self.obj._data = self.obj.reindex(labels, axis=i)._data
                     self.obj._maybe_update_cacher(clear=True)
                     self.obj.is_copy = None
 
@@ -1132,7 +1132,7 @@ def _getitem_iterable(self, key, axis=None):
             if labels.is_unique and Index(keyarr).is_unique:
 
                 try:
-                    return self.obj.reindex_axis(keyarr, axis=axis)
+                    return self.obj.reindex(keyarr, axis=axis)
                 except AttributeError:
 
                     # Series

pandas/core/internals.py

@@ -3283,8 +3283,8 @@ def apply(self, f, axes=None, filter=None, do_integrity_check=False,
 
                 for k, obj in aligned_args.items():
                     axis = getattr(obj, '_info_axis_number', 0)
-                    kwargs[k] = obj.reindex_axis(b_items, axis=axis,
-                                                 copy=align_copy)
+                    kwargs[k] = obj.reindex(b_items, axis=axis,
+                                            copy=align_copy)
 
             kwargs['mgr'] = self
             applied = getattr(b, f)(**kwargs)

pandas/core/panel.py

@@ -1197,13 +1197,21 @@ def _wrap_result(self, result, axis):
         return self._construct_return_type(result, axes)
 
     @Appender(_shared_docs['reindex'] % _shared_doc_kwargs)
-    def reindex(self, items=None, major_axis=None, minor_axis=None, **kwargs):
+    def reindex(self, labels=None,
+                items=None, major_axis=None, minor_axis=None,
+                axis=None, **kwargs):
         major_axis = (major_axis if major_axis is not None else
                       kwargs.pop('major', None))
         minor_axis = (minor_axis if minor_axis is not None else
                       kwargs.pop('minor', None))
-        return super(Panel, self).reindex(items=items, major_axis=major_axis,
-                                          minor_axis=minor_axis, **kwargs)
+        axes = self._validate_axis_style_args(
+            labels, 'labels', axes=[items, major_axis, minor_axis],
+            axis=axis, method_name='reindex')
+        if self.ndim >= 4:
+            # Hack for PanelND
+            axes = {}
+        kwargs.update(axes)
+        return super(Panel, self).reindex(**kwargs)
 
     @Appender(_shared_docs['rename'] % _shared_doc_kwargs)
     def rename(self, items=None, major_axis=None, minor_axis=None, **kwargs):

pandas/core/panel4d.py

@@ -57,4 +57,18 @@ def panel4d_init(self, data=None, labels=None, items=None, major_axis=None,
                     dtype=dtype)
 
 
+def panel4d_reindex(self, labs=None, labels=None, items=None, major_axis=None,
+                    minor_axis=None, axis=None, **kwargs):
+    # Hack for reindex_axis deprecation
+    # Ha, we used labels for two different things
+    # I think this will work still.
+    axes = self._validate_axis_style_args(
+        labs, 'labels',
+        axes=[labels, items, major_axis, minor_axis],
+        axis=axis, method_name='reindex')
+    kwargs.update(axes)
+    return super(Panel, self).reindex(**kwargs)
+
+
 Panel4D.__init__ = panel4d_init
+Panel4D.reindex = panel4d_reindex