ENH: Styler.show shorthand alternative to hide

doc/source/reference/style.rst

@@ -41,6 +41,7 @@ Style application
    Styler.format
    Styler.format_index
    Styler.hide
+   Styler.show
    Styler.set_td_classes
    Styler.set_table_styles
    Styler.set_table_attributes

doc/source/whatsnew/v1.4.0.rst

@@ -87,6 +87,7 @@ Styler
 
   - Styling and formatting of indexes has been added, with :meth:`.Styler.apply_index`, :meth:`.Styler.applymap_index` and :meth:`.Styler.format_index`. These mirror the signature of the methods already used to style and format data values, and work with both HTML, LaTeX and Excel format (:issue:`41893`, :issue:`43101`, :issue:`41993`, :issue:`41995`)
   - The new method :meth:`.Styler.hide` deprecates :meth:`.Styler.hide_index` and :meth:`.Styler.hide_columns` (:issue:`43758`)
+  - The new method :meth:`.Styler.show` provides a convenient refactorisation of :meth:`.Styler.hide` for specific rows and column labels, including ``head`` and ``tail`` options (:issue:`?????`)
   - The keyword arguments ``level`` and ``names`` have been added to :meth:`.Styler.hide` (and implicitly to the deprecated methods :meth:`.Styler.hide_index` and :meth:`.Styler.hide_columns`) for additional control of visibility of MultiIndexes and of index names (:issue:`25475`, :issue:`43404`, :issue:`43346`)
   - The :meth:`.Styler.export` and :meth:`.Styler.use` have been updated to address all of the added functionality from v1.2.0 and v1.3.0 (:issue:`40675`)
   - Global options under the category ``pd.options.styler`` have been extended to configure default ``Styler`` properties which address formatting, encoding, and HTML and LaTeX rendering. Note that formerly ``Styler`` relied on ``display.html.use_mathjax``, which has now been replaced by ``styler.html.mathjax``. (:issue:`41395`)

pandas/io/formats/style.py

@@ -2401,6 +2401,10 @@ def hide(
         -------
         self : Styler
 
+        See Also
+        --------
+        Styler.show: Show specific rows / columns.
+
         Notes
         -----
         This method has multiple functionality depending upon the combination
@@ -2557,6 +2561,93 @@ def hide(
             setattr(self, f"hide_{obj}_names", True)
         return self
 
+    def show(
+        self,
+        subset: Subset | None = None,
+        axis: Axis = 0,
+        head: int | None = None,
+        tail: int | None = None,
+    ) -> Styler:
+        """
+        Show specific rows / columns in the display.
+
+        .. versionadded:: 1.4.0
+
+        Parameters
+        ----------
+        subset : label, array-like, IndexSlice, optional
+            A valid 1d input or single key along the axis within
+            `DataFrame.loc[<subset>, :]` or `DataFrame.loc[:, <subset>]` depending
+            upon ``axis``, to limit ``data`` to select specific rows / columns.
+        axis : {"index", 0, "columns", 1}
+            Apply to the index or columns.
+        head : int, optional
+            The number of rows / columns at the start of the axis-index to show.
+        tail : int, optional
+            The number of rows / columns at the end of the axis-index to show.
+
+        Returns
+        -------
+        self : Styler
+
+        See Also
+        --------
+        Styler.hide: Hide the entire index / columns, or specific rows / columns.
+
+        Notes
+        -----
+        This is a simplified wrapper of :meth:`Styler.hide`, where the inputs are
+        internally restructured to a call to `Styler.hide`. It is recommended to
+        use `Styler.show` exclusively, and with only one call per axis, as a form of
+        convenient data exploration. For more specific control of removing items from
+        the display it is recommended to use `Styler.hide`, with as many successive
+        calls as is required.
+
+        The technical explanation for this recommendation is that at instantiation
+        `Styler` is configured to display all datapoints and all aspects of the
+        index and column headers of a DataFrame,
+        but `Styler.hide` can be called to selectively, and successively, remove
+        items from that default display.
+
+        For example, given an index of `[0, 1, 2, 3]`, calling:
+
+        .. code-block:: python
+
+           styler.hide([0, 1]).hide([2, 3])
+
+        will first hide the first 2 index labels and then, subsequently, also hide the
+        final 2 labels, resulting in hiding all of the rows and displaying none.
+
+        In this case `styler.show([0, 1])` is refactored as the call
+        `styler.hide([v for v in styler.index if v not in [0, 1]])` which is
+        equivalently `styler.hide([2, 3])` so performing:
+
+        .. code-block:: python
+
+           styler.hide([0, 1]).show([0, 1])
+
+        is effectively the same as the above and will also result in all rows hidden.
+
+        `Styler.hide` will always only add items to the set that is considered hidden.
+        It never removes items, that have been previously added, from that set to make
+        them visible again. This is done to provide consistent method chaining.
+        """
+        axis = self.data._get_axis_number(axis)
+        obj = "index" if axis == 0 else "columns"
+
+        visible = []
+        if head is not None:
+            visible.extend(getattr(self, obj)[:head])
+        if tail is not None:
+            visible.extend(getattr(self, obj)[-tail:])
+        if subset is not None:
+            subset_ = IndexSlice[subset, :] if axis == 0 else IndexSlice[:, subset]
+            visible.extend(getattr(self.data.loc[non_reducing_slice(subset_)], obj))
+
+        return self.hide(
+            subset=[v for v in getattr(self, obj) if v not in visible], axis=axis
+        )
+
     # -----------------------------------------------------------------------
     # A collection of "builtin" styles
     # -----------------------------------------------------------------------

pandas/tests/io/formats/style/test_style.py

@@ -1548,3 +1548,25 @@ def test_col_trimming_hide_columns():
         assert ctx["head"][0][c + 2]["is_visible"] == vals[1]
 
     assert len(ctx["body"][0]) == 6  # index + 2 hidden + 2 visible + trimming col
+
+
+@pytest.mark.parametrize(
+    "kwargs, exp",
+    [
+        ({"head": 2}, [3, 4]),
+        ({"tail": 2}, [1, 2]),
+        ({"subset": [2, 3]}, [1, 4]),
+        ({"head": 1, "tail": 1}, [2, 3]),
+        ({"head": 2, "subset": [2, 3]}, [4]),
+        ({"tail": 2, "subset": [2, 3]}, [1]),
+        ({"tail": 1, "subset": [2, 3], "head": 1}, []),
+    ],
+)
+@pytest.mark.parametrize("axis", ["index", "columns"])
+def test_show(kwargs, exp, axis):
+    df = DataFrame(np.random.randn(4, 4), index=[1, 2, 3, 4], columns=[1, 2, 3, 4])
+    styler = Styler(df, uuid_len=0)
+    result = styler.show(axis=axis, **kwargs)._translate(True, True)
+    styler2 = Styler(df, uuid_len=0)
+    expected = styler2.hide(subset=exp, axis=axis)._translate(True, True)
+    assert result == expected