From b0bfab7c43c58e8c4ee2799ebd4747caa4530d75 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Sun, 2 May 2021 13:18:42 +0200
Subject: [PATCH 01/16] ENH: make hide_index and hide_columns consistent in
 functionality

---
 pandas/io/formats/style.py        | 172 +++++++++++++++++++++++++++---
 pandas/io/formats/style_render.py |  69 ++++++------
 2 files changed, 197 insertions(+), 44 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 02e1369a05b93..753c385b1abe9 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -28,6 +28,7 @@
 from pandas.util._decorators import doc
 
 import pandas as pd
+from pandas import IndexSlice
 from pandas.api.types import is_list_like
 from pandas.core import generic
 import pandas.core.common as com
@@ -640,7 +641,7 @@ def apply(
     def _applymap(self, func: Callable, subset=None, **kwargs) -> Styler:
         func = partial(func, **kwargs)  # applymap doesn't take kwargs?
         if subset is None:
-            subset = pd.IndexSlice[:]
+            subset = IndexSlice[:]
         subset = non_reducing_slice(subset)
         result = self.data.loc[subset].applymap(func)
         self._update_ctx(result)
@@ -1035,37 +1036,180 @@ def set_na_rep(self, na_rep: str) -> StylerRenderer:
         self.na_rep = na_rep
         return self.format(na_rep=na_rep, precision=self.precision)
 
-    def hide_index(self) -> Styler:
+    def hide_index(self, subset=None, show: bool = False) -> Styler:
         """
-        Hide any indices from rendering.
+        Hide the entire index, or specific keys in the index from rendering.
+
+        This method has dual functionality:
+
+          - if ``subset`` is ``None`` then the entire index will be hidden whilst
+            displaying all data-rows.
+          - if a ``subset`` is given then those specific rows will be hidden whilst the
+            index itself remains visible.
+
+        Parameters
+        ----------
+        subset : IndexSlice
+            An argument to ``DataFrame.loc`` along the index, that identifies which
+            index key rows will be hidden.
+        show : bool
+            Indicates whether the function `hides` the index or selected rows,
+            by default, or operates inversely by exclusively showing them.
 
         Returns
         -------
         self : Styler
+
+        See Also
+        --------
+        Styler.hide_columns: Hide the entire column headers row, or specific columns.
+
+        Examples
+        --------
+        Hide the index and retain the data values:
+
+        >>> midx = pd.MultiIndex.from_product([["x", "y"], ["a", "b", "c"]])
+        >>> df = pd.DataFrame(np.random.randn(6,6), index=midx, columns=midx)
+        >>> df.style.format("{:.1f}").hide_index()
+                         x                    y
+           a      b      c      a      b      c
+         0.1    0.0    0.4    1.3    0.6   -1.4
+         0.7    1.0    1.3    1.5   -0.0   -0.2
+         1.4   -0.8    1.6   -0.2   -0.4   -0.3
+         0.4    1.0   -0.2   -0.8   -1.2    1.1
+        -0.6    1.2    1.8    1.9    0.3    0.3
+         0.8    0.5   -0.3    1.2    2.2   -0.8
+
+        Hide specific rows but retain the index:
+
+        >>> df.style.format("{:.1f}").hide_index(subset=(slice(None), ["a", "c"]))
+                                 x                    y
+                   a      b      c      a      b      c
+        x   b    0.7    1.0    1.3    1.5   -0.0   -0.2
+        y   b   -0.6    1.2    1.8    1.9    0.3    0.3
+
+        Hide specific rows and the index:
+
+        >>> df.style.format("{:.1f}").hide_index(subset=(slice(None), ["a", "c"]))
+        ...     .hide_index()
+                         x                    y
+           a      b      c      a      b      c
+         0.7    1.0    1.3    1.5   -0.0   -0.2
+        -0.6    1.2    1.8    1.9    0.3    0.3
+
+        Exclusively show specific rows:
+
+        >>> df.style.format("{:.1f}")
+        ...     .hide_index(subset=(slice(None), ["b"]), show=True)
+                                 x                    y
+                   a      b      c      a      b      c
+        x   b    0.7    1.0    1.3    1.5   -0.0   -0.2
+        y   b   -0.6    1.2    1.8    1.9    0.3    0.3
         """
-        self.hidden_index = True
+        if subset is None:
+            self.hidden_index = not show
+        else:
+            subset = IndexSlice[subset, :]
+            subset = non_reducing_slice(subset)
+            hide = self.data.loc[subset]
+            if show:  # invert the display
+                hide = self.data.loc[~self.data.index.isin(hide.index.to_list()), :]
+            hrows = self.index.get_indexer_for(hide.index)
+            # error: Incompatible types in assignment (expression has type
+            # "ndarray", variable has type "Sequence[int]")
+            self.hidden_rows = hrows  # type: ignore[assignment]
         return self
 
-    def hide_columns(self, subset) -> Styler:
+    def hide_columns(self, subset=None, show: bool = False) -> Styler:
         """
-        Hide columns from rendering.
+        Hide the column headers or specific keys in the columns from rendering.
+
+        This method has dual functionality:
+
+          - if ``subset`` is ``None`` then the entire column headers row will be hidden
+            whilst the data-values remain visible.
+          - if a ``subset`` is given then those specific columns, including the
+            data-values will be hidden, whilst the column headers row remains visible.
 
         Parameters
         ----------
         subset : IndexSlice
-            An argument to ``DataFrame.loc`` that identifies which columns
-            are hidden.
+            An argument to ``DataFrame.loc`` along the columns, that identifies which
+            columns keys will be hidden.
+        show : bool
+            Indicates whether the function `hides` the columns headers or selected
+            columns, by default, or operates inversely by exclusively showing them.
 
         Returns
         -------
         self : Styler
+
+        See Also
+        --------
+        Styler.hide_index: Hide the entire index, or specific keys in the index.
+
+        Examples
+        --------
+        Hide column headers and retain the data values:
+
+        >>> midx = pd.MultiIndex.from_product([["x", "y"], ["a", "b", "c"]])
+        >>> df = pd.DataFrame(np.random.randn(6,6), index=midx, columns=midx)
+        >>> df.style.format("{:.1f}").hide_columns()
+        x   d    0.1    0.0    0.4    1.3    0.6   -1.4
+            e    0.7    1.0    1.3    1.5   -0.0   -0.2
+            f    1.4   -0.8    1.6   -0.2   -0.4   -0.3
+        y   d    0.4    1.0   -0.2   -0.8   -1.2    1.1
+            e   -0.6    1.2    1.8    1.9    0.3    0.3
+            f    0.8    0.5   -0.3    1.2    2.2   -0.8
+
+        Hide specific columns but retain the column headers:
+
+        >>> df.style.format("{:.1f}").hide_columns(subset=(slice(None), ["a", "c"]))
+                   x      y
+                   b      b
+        x   a    0.0    0.6
+            b    1.0   -0.0
+            c   -0.8   -0.4
+        y   a    1.0   -1.2
+            b    1.2    0.3
+            c    0.5    2.2
+
+        Hide specific columns and the column headers:
+
+        >>> df.style.format("{:.1f}").hide_columns(subset=(slice(None), ["a", "c"]))
+        ...     .hide_columns()
+        x   a    0.0    0.6
+            b    1.0   -0.0
+            c   -0.8   -0.4
+        y   a    1.0   -1.2
+            b    1.2    0.3
+            c    0.5    2.2
+
+        Exclusively show specific columns:
+
+        >>> df.style.format("{:.1f}")
+        ...     .hide_columns(subset=(slice(None), ["b"]), show=True)
+                   x      y
+                   b      b
+        x   a    0.0    0.6
+            b    1.0   -0.0
+            c   -0.8   -0.4
+        y   a    1.0   -1.2
+            b    1.2    0.3
+            c    0.5    2.2
         """
-        subset = non_reducing_slice(subset)
-        hidden_df = self.data.loc[subset]
-        hcols = self.columns.get_indexer_for(hidden_df.columns)
-        # error: Incompatible types in assignment (expression has type
-        # "ndarray", variable has type "Sequence[int]")
-        self.hidden_columns = hcols  # type: ignore[assignment]
+        if subset is None:
+            self.hidden_colheads = not show
+        else:
+            subset = IndexSlice[:, subset]
+            subset = non_reducing_slice(subset)
+            hide = self.data.loc[subset]
+            if show:  # invert the display
+                hide = self.data.loc[:, ~self.data.columns.isin(hide.columns.to_list())]
+            hcols = self.columns.get_indexer_for(hide.columns)
+            # error: Incompatible types in assignment (expression has type
+            # "ndarray", variable has type "Sequence[int]")
+            self.hidden_columns = hcols  # type: ignore[assignment]
         return self
 
     # -----------------------------------------------------------------------
diff --git a/pandas/io/formats/style_render.py b/pandas/io/formats/style_render.py
index 0253852fbb39a..7b34b67fb5040 100644
--- a/pandas/io/formats/style_render.py
+++ b/pandas/io/formats/style_render.py
@@ -98,6 +98,8 @@ def __init__(
 
         # add rendering variables
         self.hidden_index: bool = False
+        self.hidden_rows: Sequence[int] = []
+        self.hidden_colheads: bool = False
         self.hidden_columns: Sequence[int] = []
         self.ctx: DefaultDict[tuple[int, int], CSSList] = defaultdict(list)
         self.cell_context: DefaultDict[tuple[int, int], str] = defaultdict(str)
@@ -209,37 +211,38 @@ def _translate_header(
 
         head = []
         # 1) column headers
-        for r in range(self.data.columns.nlevels):
-            index_blanks = [
-                _element("th", blank_class, blank_value, not self.hidden_index)
-            ] * (self.data.index.nlevels - 1)
-
-            name = self.data.columns.names[r]
-            column_name = [
-                _element(
-                    "th",
-                    f"{blank_class if name is None else index_name_class} level{r}",
-                    name if name is not None else blank_value,
-                    not self.hidden_index,
-                )
-            ]
-
-            if clabels:
-                column_headers = [
+        if not self.hidden_colheads:
+            for r in range(self.data.columns.nlevels):
+                index_blanks = [
+                    _element("th", blank_class, blank_value, not self.hidden_index)
+                ] * (self.data.index.nlevels - 1)
+
+                name = self.data.columns.names[r]
+                column_name = [
                     _element(
                         "th",
-                        f"{col_heading_class} level{r} col{c}",
-                        value,
-                        _is_visible(c, r, col_lengths),
-                        attributes=(
-                            f'colspan="{col_lengths.get((r, c), 0)}"'
-                            if col_lengths.get((r, c), 0) > 1
-                            else ""
-                        ),
+                        f"{blank_class if name is None else index_name_class} level{r}",
+                        name if name is not None else blank_value,
+                        not self.hidden_index,
                     )
-                    for c, value in enumerate(clabels[r])
                 ]
-                head.append(index_blanks + column_name + column_headers)
+
+                if clabels:
+                    column_headers = [
+                        _element(
+                            "th",
+                            f"{col_heading_class} level{r} col{c}",
+                            value,
+                            _is_visible(c, r, col_lengths),
+                            attributes=(
+                                f'colspan="{col_lengths.get((r, c), 0)}"'
+                                if col_lengths.get((r, c), 0) > 1
+                                else ""
+                            ),
+                        )
+                        for c, value in enumerate(clabels[r])
+                    ]
+                    head.append(index_blanks + column_name + column_headers)
 
         # 2) index names
         if (
@@ -281,7 +284,7 @@ def _translate_body(self, data_class, row_heading_class):
         <style></style> block
         """
         # for sparsifying a MultiIndex
-        idx_lengths = _get_level_lengths(self.index)
+        idx_lengths = _get_level_lengths(self.index, self.hidden_rows)
 
         rlabels = self.data.index.tolist()
         if self.data.index.nlevels == 1:
@@ -316,7 +319,7 @@ def _translate_body(self, data_class, row_heading_class):
                     "td",
                     f"{data_class} row{r} col{c}{cls}",
                     value,
-                    (c not in self.hidden_columns),
+                    (c not in self.hidden_columns and r not in self.hidden_rows),
                     attributes="",
                     display_value=self._display_funcs[(r, c)](value),
                 )
@@ -565,7 +568,13 @@ def _get_level_lengths(index, hidden_elements=None):
                 last_label = j
                 lengths[(i, last_label)] = 0
             elif j not in hidden_elements:
-                lengths[(i, last_label)] += 1
+                if lengths[(i, last_label)] == 0:
+                    # if the previous iteration was first-of-kind but hidden then offset
+                    last_label = j
+                    lengths[(i, last_label)] = 1
+                else:
+                    # else add to previous iteration
+                    lengths[(i, last_label)] += 1
 
     non_zero_lengths = {
         element: length for element, length in lengths.items() if length >= 1

From c615b08ae2ba27be9b643270640af69fce2e1557 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Sun, 2 May 2021 16:51:46 +0200
Subject: [PATCH 02/16] DOC: improve specificity

---
 pandas/io/formats/style.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 753c385b1abe9..0a3217148f487 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -1050,8 +1050,8 @@ def hide_index(self, subset=None, show: bool = False) -> Styler:
         Parameters
         ----------
         subset : IndexSlice
-            An argument to ``DataFrame.loc`` along the index, that identifies which
-            index key rows will be hidden.
+            An argument to ``DataFrame.loc[subset, :]``, i.e. along the index, that
+            identifies which index key rows will be hidden.
         show : bool
             Indicates whether the function `hides` the index or selected rows,
             by default, or operates inversely by exclusively showing them.
@@ -1134,8 +1134,8 @@ def hide_columns(self, subset=None, show: bool = False) -> Styler:
         Parameters
         ----------
         subset : IndexSlice
-            An argument to ``DataFrame.loc`` along the columns, that identifies which
-            columns keys will be hidden.
+            An argument to ``DataFrame.loc[:, subset]``, i.e. along the columns, that
+            identifies which columns keys will be hidden.
         show : bool
             Indicates whether the function `hides` the columns headers or selected
             columns, by default, or operates inversely by exclusively showing them.

From 38b74075bdf028b5474cf6d901fda3d03c41dfe4 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Sun, 2 May 2021 17:37:10 +0200
Subject: [PATCH 03/16] TST: add tests for hide_index(subset=)

---
 pandas/tests/io/formats/style/test_style.py | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/pandas/tests/io/formats/style/test_style.py b/pandas/tests/io/formats/style/test_style.py
index 3b614be770bc5..147fc27d653f0 100644
--- a/pandas/tests/io/formats/style/test_style.py
+++ b/pandas/tests/io/formats/style/test_style.py
@@ -1152,7 +1152,8 @@ def test_hide_columns_mult_levels(self):
 
         # hide first column only
         ctx = df.style.hide_columns([("b", 0)])._translate()
-        assert ctx["head"][0][2]["is_visible"]  # b
+        assert not ctx["head"][0][2]["is_visible"]  # b
+        assert ctx["head"][0][3]["is_visible"]  # b
         assert not ctx["head"][1][2]["is_visible"]  # 0
         assert not ctx["body"][1][2]["is_visible"]  # 3
         assert ctx["body"][1][3]["is_visible"]
@@ -1168,6 +1169,18 @@ def test_hide_columns_mult_levels(self):
         assert ctx["body"][1][2]["is_visible"]
         assert ctx["body"][1][2]["display_value"] == 3
 
+        # hide top row level, which hides both rows
+        ctx = df.style.hide_index("a")._translate()
+        for i in [0, 1, 2, 3]:
+            assert not ctx["body"][0][i]["is_visible"]
+            assert not ctx["body"][1][i]["is_visible"]
+
+        # hide first row only
+        ctx = df.style.hide_index(("a", 0))._translate()
+        for i in [0, 1, 2, 3]:
+            assert not ctx["body"][0][i]["is_visible"]
+            assert ctx["body"][1][i]["is_visible"]
+
     def test_pipe(self):
         def set_caption_from_template(styler, a, b):
             return styler.set_caption(f"Dataframe with a = {a} and b = {b}")

From 40504dba054fbf7b56c7df1bc27bb1ecbd88f0fa Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Sun, 2 May 2021 17:45:48 +0200
Subject: [PATCH 04/16] TST: add tests for hide_columns(subset=None)

---
 pandas/tests/io/formats/style/test_style.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pandas/tests/io/formats/style/test_style.py b/pandas/tests/io/formats/style/test_style.py
index 147fc27d653f0..8b9667cf8a872 100644
--- a/pandas/tests/io/formats/style/test_style.py
+++ b/pandas/tests/io/formats/style/test_style.py
@@ -1052,6 +1052,14 @@ def test_mi_sparse_column_names(self):
         ]
         assert head == expected
 
+    def test_hide_column_headers(self):
+        ctx = self.styler.hide_columns()._translate()
+        assert len(ctx["head"]) == 0  # no header entries with an unnamed index
+
+        self.df.index.name = "some_name"
+        ctx = self.df.style.hide_columns()._translate()
+        assert len(ctx["head"]) == 1  # only a single row for index names: no col heads
+
     def test_hide_single_index(self):
         # GH 14194
         # single unnamed index
@@ -1120,7 +1128,7 @@ def test_hide_columns_single_level(self):
         assert not ctx["body"][0][1]["is_visible"]  # col A, row 1
         assert not ctx["body"][1][2]["is_visible"]  # col B, row 1
 
-    def test_hide_columns_mult_levels(self):
+    def test_hide_columns_index_mult_levels(self):
         # GH 14194
         # setup dataframe with multiple column levels and indices
         i1 = pd.MultiIndex.from_arrays(

From 67598a4eeaf5b423570aecdf4171e5bd6d3f82cd Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Wed, 5 May 2021 16:43:15 +0200
Subject: [PATCH 05/16] remove show option

---
 pandas/io/formats/style.py | 31 ++++---------------------------
 1 file changed, 4 insertions(+), 27 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 0a3217148f487..84ee9bd9cff94 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -1036,7 +1036,7 @@ def set_na_rep(self, na_rep: str) -> StylerRenderer:
         self.na_rep = na_rep
         return self.format(na_rep=na_rep, precision=self.precision)
 
-    def hide_index(self, subset=None, show: bool = False) -> Styler:
+    def hide_index(self, subset=None) -> Styler:
         """
         Hide the entire index, or specific keys in the index from rendering.
 
@@ -1052,9 +1052,6 @@ def hide_index(self, subset=None, show: bool = False) -> Styler:
         subset : IndexSlice
             An argument to ``DataFrame.loc[subset, :]``, i.e. along the index, that
             identifies which index key rows will be hidden.
-        show : bool
-            Indicates whether the function `hides` the index or selected rows,
-            by default, or operates inversely by exclusively showing them.
 
         Returns
         -------
@@ -1107,20 +1104,18 @@ def hide_index(self, subset=None, show: bool = False) -> Styler:
         y   b   -0.6    1.2    1.8    1.9    0.3    0.3
         """
         if subset is None:
-            self.hidden_index = not show
+            self.hidden_index = True
         else:
             subset = IndexSlice[subset, :]
             subset = non_reducing_slice(subset)
             hide = self.data.loc[subset]
-            if show:  # invert the display
-                hide = self.data.loc[~self.data.index.isin(hide.index.to_list()), :]
             hrows = self.index.get_indexer_for(hide.index)
             # error: Incompatible types in assignment (expression has type
             # "ndarray", variable has type "Sequence[int]")
             self.hidden_rows = hrows  # type: ignore[assignment]
         return self
 
-    def hide_columns(self, subset=None, show: bool = False) -> Styler:
+    def hide_columns(self, subset=None) -> Styler:
         """
         Hide the column headers or specific keys in the columns from rendering.
 
@@ -1136,9 +1131,6 @@ def hide_columns(self, subset=None, show: bool = False) -> Styler:
         subset : IndexSlice
             An argument to ``DataFrame.loc[:, subset]``, i.e. along the columns, that
             identifies which columns keys will be hidden.
-        show : bool
-            Indicates whether the function `hides` the columns headers or selected
-            columns, by default, or operates inversely by exclusively showing them.
 
         Returns
         -------
@@ -1184,28 +1176,13 @@ def hide_columns(self, subset=None, show: bool = False) -> Styler:
         y   a    1.0   -1.2
             b    1.2    0.3
             c    0.5    2.2
-
-        Exclusively show specific columns:
-
-        >>> df.style.format("{:.1f}")
-        ...     .hide_columns(subset=(slice(None), ["b"]), show=True)
-                   x      y
-                   b      b
-        x   a    0.0    0.6
-            b    1.0   -0.0
-            c   -0.8   -0.4
-        y   a    1.0   -1.2
-            b    1.2    0.3
-            c    0.5    2.2
         """
         if subset is None:
-            self.hidden_colheads = not show
+            self.hidden_colheads = True
         else:
             subset = IndexSlice[:, subset]
             subset = non_reducing_slice(subset)
             hide = self.data.loc[subset]
-            if show:  # invert the display
-                hide = self.data.loc[:, ~self.data.columns.isin(hide.columns.to_list())]
             hcols = self.columns.get_indexer_for(hide.columns)
             # error: Incompatible types in assignment (expression has type
             # "ndarray", variable has type "Sequence[int]")

From f05757a96f97ef72c195bd33f546b5330d4fff29 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Wed, 5 May 2021 16:44:28 +0200
Subject: [PATCH 06/16] remove show option

---
 pandas/io/formats/style.py | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 84ee9bd9cff94..6e054212ac360 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -1093,15 +1093,6 @@ def hide_index(self, subset=None) -> Styler:
            a      b      c      a      b      c
          0.7    1.0    1.3    1.5   -0.0   -0.2
         -0.6    1.2    1.8    1.9    0.3    0.3
-
-        Exclusively show specific rows:
-
-        >>> df.style.format("{:.1f}")
-        ...     .hide_index(subset=(slice(None), ["b"]), show=True)
-                                 x                    y
-                   a      b      c      a      b      c
-        x   b    0.7    1.0    1.3    1.5   -0.0   -0.2
-        y   b   -0.6    1.2    1.8    1.9    0.3    0.3
         """
         if subset is None:
             self.hidden_index = True

From 57aa0fcbb2ac834df4f13015e5cbf291d9ea9353 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Wed, 12 May 2021 11:17:40 +0200
Subject: [PATCH 07/16] type subset

---
 pandas/io/formats/style.py        | 19 ++++++++++++-------
 pandas/io/formats/style_render.py | 11 ++++++++---
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 898057f8cf4e0..4b0dc20b47196 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -44,6 +44,7 @@
     CSSProperties,
     CSSStyles,
     StylerRenderer,
+    Subset,
     Tooltips,
     maybe_convert_css_to_tuples,
     non_reducing_slice,
@@ -1051,7 +1052,7 @@ def set_na_rep(self, na_rep: str) -> StylerRenderer:
         self.na_rep = na_rep
         return self.format(na_rep=na_rep, precision=self.precision)
 
-    def hide_index(self, subset=None) -> Styler:
+    def hide_index(self, subset: Subset | None = None) -> Styler:
         """
         Hide the entire index, or specific keys in the index from rendering.
 
@@ -1062,6 +1063,8 @@ def hide_index(self, subset=None) -> Styler:
           - if a ``subset`` is given then those specific rows will be hidden whilst the
             index itself remains visible.
 
+        .. versionchanged:: 1.3.0
+
         Parameters
         ----------
         subset : IndexSlice
@@ -1112,8 +1115,8 @@ def hide_index(self, subset=None) -> Styler:
         if subset is None:
             self.hidden_index = True
         else:
-            subset = IndexSlice[subset, :]
-            subset = non_reducing_slice(subset)
+            subset_ = IndexSlice[subset, :]  # new var so mypy reads not Optional
+            subset = non_reducing_slice(subset_)
             hide = self.data.loc[subset]
             hrows = self.index.get_indexer_for(hide.index)
             # error: Incompatible types in assignment (expression has type
@@ -1121,7 +1124,7 @@ def hide_index(self, subset=None) -> Styler:
             self.hidden_rows = hrows  # type: ignore[assignment]
         return self
 
-    def hide_columns(self, subset=None) -> Styler:
+    def hide_columns(self, subset: Subset | None = None) -> Styler:
         """
         Hide the column headers or specific keys in the columns from rendering.
 
@@ -1132,6 +1135,8 @@ def hide_columns(self, subset=None) -> Styler:
           - if a ``subset`` is given then those specific columns, including the
             data-values will be hidden, whilst the column headers row remains visible.
 
+        .. versionchanged:: 1.3.0
+
         Parameters
         ----------
         subset : IndexSlice
@@ -1186,8 +1191,8 @@ def hide_columns(self, subset=None) -> Styler:
         if subset is None:
             self.hidden_colheads = True
         else:
-            subset = IndexSlice[:, subset]
-            subset = non_reducing_slice(subset)
+            subset_ = IndexSlice[:, subset]  # new var so mypy reads not Optional
+            subset = non_reducing_slice(subset_)
             hide = self.data.loc[subset]
             hcols = self.columns.get_indexer_for(hide.columns)
             # error: Incompatible types in assignment (expression has type
@@ -1779,7 +1784,7 @@ def highlight_between(
 
     def highlight_quantile(
         self,
-        subset: IndexLabel | None = None,
+        subset: Subset | None = None,
         color: str = "yellow",
         axis: Axis | None = 0,
         q_left: float = 0.0,
diff --git a/pandas/io/formats/style_render.py b/pandas/io/formats/style_render.py
index 9cdc1b40317e6..36689e55b2b18 100644
--- a/pandas/io/formats/style_render.py
+++ b/pandas/io/formats/style_render.py
@@ -55,6 +55,7 @@ class CSSDict(TypedDict):
 
 
 CSSStyles = List[CSSDict]
+Subset = Union[slice, Sequence]
 
 
 class StylerRenderer:
@@ -338,7 +339,7 @@ def _translate_body(self, data_class, row_heading_class):
     def format(
         self,
         formatter: ExtFormatter | None = None,
-        subset: slice | Sequence[Any] | None = None,
+        subset: Subset | None = None,
         na_rep: str | None = None,
         precision: int | None = None,
         decimal: str = ".",
@@ -702,7 +703,7 @@ def _maybe_wrap_formatter(
         return lambda x: na_rep if isna(x) else func_2(x)
 
 
-def non_reducing_slice(slice_):
+def non_reducing_slice(slice_: Subset):
     """
     Ensure that a slice doesn't reduce to a Series or Scalar.
 
@@ -739,7 +740,11 @@ def pred(part) -> bool:
             # slice(a, b, c)
             slice_ = [slice_]  # to tuplize later
     else:
-        slice_ = [part if pred(part) else [part] for part in slice_]
+        # error: Item "slice" of "Union[slice, Sequence[Any]]" has no attribute
+        # "__iter__" (not iterable)
+        # this else branch is exclusively list_list so can iterate.
+        slice_ = [p if pred(p) else [p] for p in slice_]  # type: ignore[union-attr]
+
     return tuple(slice_)
 
 

From 515707dca167bca9ebb35e35bd2dac8837b065be Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Thu, 20 May 2021 09:49:38 +0200
Subject: [PATCH 08/16] docstring for subset

---
 pandas/io/formats/style.py | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 87a818d62cdfa..0e5f983dfe477 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -1071,9 +1071,10 @@ def hide_index(self, subset: Subset | None = None) -> Styler:
 
         Parameters
         ----------
-        subset : IndexSlice
-            An argument to ``DataFrame.loc[subset, :]``, i.e. along the index, that
-            identifies which index key rows will be hidden.
+        subset : label, array-like, IndexSlice
+            A valid 1d input or single key along the index axis within
+            `DataFrame.loc[<subset>, :]`, to limit ``data`` to *before* applying
+            the function.
 
         Returns
         -------
@@ -1143,9 +1144,10 @@ def hide_columns(self, subset: Subset | None = None) -> Styler:
 
         Parameters
         ----------
-        subset : IndexSlice
-            An argument to ``DataFrame.loc[:, subset]``, i.e. along the columns, that
-            identifies which columns keys will be hidden.
+        subset : label, array-like, IndexSlice
+            A valid 1d input or single key along the columns axis within
+            `DataFrame.loc[:, <subset>]`, to limit ``data`` to *before* applying
+            the function.
 
         Returns
         -------

From fa8eceef422c2a6fd96c69b9fbc84b6dbf6c573c Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Thu, 20 May 2021 10:01:08 +0200
Subject: [PATCH 09/16] simpler examples

---
 pandas/io/formats/style.py | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 0e5f983dfe477..9f3e166b21aba 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -1071,7 +1071,7 @@ def hide_index(self, subset: Subset | None = None) -> Styler:
 
         Parameters
         ----------
-        subset : label, array-like, IndexSlice
+        subset : label, array-like, IndexSlice, optional
             A valid 1d input or single key along the index axis within
             `DataFrame.loc[<subset>, :]`, to limit ``data`` to *before* applying
             the function.
@@ -1086,6 +1086,13 @@ def hide_index(self, subset: Subset | None = None) -> Styler:
 
         Examples
         --------
+        Simple application hiding specific rows:
+
+        >>> df = pd.DataFrame([[1,2], [3,4], [5,6]], index=["a", "b", "c"])
+        >>> df.style.hide_index(["a", "b"])
+             0    1
+        c    5    6
+
         Hide the index and retain the data values:
 
         >>> midx = pd.MultiIndex.from_product([["x", "y"], ["a", "b", "c"]])
@@ -1144,7 +1151,7 @@ def hide_columns(self, subset: Subset | None = None) -> Styler:
 
         Parameters
         ----------
-        subset : label, array-like, IndexSlice
+        subset : label, array-like, IndexSlice, optional
             A valid 1d input or single key along the columns axis within
             `DataFrame.loc[:, <subset>]`, to limit ``data`` to *before* applying
             the function.
@@ -1159,6 +1166,14 @@ def hide_columns(self, subset: Subset | None = None) -> Styler:
 
         Examples
         --------
+        Simple application hiding specific rows:
+
+        >>> df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], columns=["a", "b", "c"])
+        >>> df.style.hide_columns(["a", "b"])
+             c
+        0    3
+        1    6
+
         Hide column headers and retain the data values:
 
         >>> midx = pd.MultiIndex.from_product([["x", "y"], ["a", "b", "c"]])

From 0704210e5ef0abfc3c576bc52ee286d60cee6670 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Thu, 20 May 2021 10:09:11 +0200
Subject: [PATCH 10/16] nomenclature: hide_columns_

---
 pandas/io/formats/style.py        | 2 +-
 pandas/io/formats/style_render.py | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 9f3e166b21aba..be4abbdec4ee6 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -1210,7 +1210,7 @@ def hide_columns(self, subset: Subset | None = None) -> Styler:
             c    0.5    2.2
         """
         if subset is None:
-            self.hidden_colheads = True
+            self.hide_columns_ = True
         else:
             subset_ = IndexSlice[:, subset]  # new var so mypy reads not Optional
             subset = non_reducing_slice(subset_)
diff --git a/pandas/io/formats/style_render.py b/pandas/io/formats/style_render.py
index 1b0b83b0ec167..a89c91a4708c9 100644
--- a/pandas/io/formats/style_render.py
+++ b/pandas/io/formats/style_render.py
@@ -97,8 +97,8 @@ def __init__(
 
         # add rendering variables
         self.hidden_index: bool = False
+        self.hide_columns_: bool = False
         self.hidden_rows: Sequence[int] = []
-        self.hidden_colheads: bool = False
         self.hidden_columns: Sequence[int] = []
         self.ctx: DefaultDict[tuple[int, int], CSSList] = defaultdict(list)
         self.cell_context: DefaultDict[tuple[int, int], str] = defaultdict(str)
@@ -259,7 +259,7 @@ def _translate_header(
 
         head = []
         # 1) column headers
-        if not self.hidden_colheads:
+        if not self.hide_columns_:
             for r in range(self.data.columns.nlevels):
                 index_blanks = [
                     _element("th", blank_class, blank_value, not self.hidden_index)

From cb58422af3868ee43d8a4ae5f53360b9fcf5d55d Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Thu, 20 May 2021 10:16:13 +0200
Subject: [PATCH 11/16] nomenclature: hide_index_

---
 pandas/io/formats/style.py                  |  6 +++---
 pandas/io/formats/style_render.py           | 10 +++++-----
 pandas/tests/io/formats/style/test_style.py |  8 ++++----
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index be4abbdec4ee6..120decdc681c5 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -499,7 +499,7 @@ def _copy(self, deepcopy: bool = False) -> Styler:
         )
 
         styler.uuid = self.uuid
-        styler.hidden_index = self.hidden_index
+        styler.hide_index_ = self.hide_index_
 
         if deepcopy:
             styler.ctx = copy.deepcopy(self.ctx)
@@ -538,7 +538,7 @@ def clear(self) -> None:
         self.cell_context.clear()
         self._todo.clear()
 
-        self.hidden_index = False
+        self.hide_index_ = False
         self.hidden_columns = []
         # self.format and self.table_styles may be dependent on user
         # input in self.__init__()
@@ -1125,7 +1125,7 @@ def hide_index(self, subset: Subset | None = None) -> Styler:
         -0.6    1.2    1.8    1.9    0.3    0.3
         """
         if subset is None:
-            self.hidden_index = True
+            self.hide_index_ = True
         else:
             subset_ = IndexSlice[subset, :]  # new var so mypy reads not Optional
             subset = non_reducing_slice(subset_)
diff --git a/pandas/io/formats/style_render.py b/pandas/io/formats/style_render.py
index a89c91a4708c9..ba965b49afab4 100644
--- a/pandas/io/formats/style_render.py
+++ b/pandas/io/formats/style_render.py
@@ -96,7 +96,7 @@ def __init__(
         self.cell_ids = cell_ids
 
         # add rendering variables
-        self.hidden_index: bool = False
+        self.hide_index_: bool = False
         self.hide_columns_: bool = False
         self.hidden_rows: Sequence[int] = []
         self.hidden_columns: Sequence[int] = []
@@ -262,7 +262,7 @@ def _translate_header(
         if not self.hide_columns_:
             for r in range(self.data.columns.nlevels):
                 index_blanks = [
-                    _element("th", blank_class, blank_value, not self.hidden_index)
+                    _element("th", blank_class, blank_value, not self.hide_index_)
                 ] * (self.data.index.nlevels - 1)
 
                 name = self.data.columns.names[r]
@@ -271,7 +271,7 @@ def _translate_header(
                         "th",
                         f"{blank_class if name is None else index_name_class} level{r}",
                         name if name is not None else blank_value,
-                        not self.hidden_index,
+                        not self.hide_index_,
                     )
                 ]
 
@@ -296,7 +296,7 @@ def _translate_header(
         if (
             self.data.index.names
             and com.any_not_none(*self.data.index.names)
-            and not self.hidden_index
+            and not self.hide_index_
         ):
             index_names = [
                 _element(
@@ -363,7 +363,7 @@ def _translate_body(
                     "th",
                     f"{row_heading_class} level{c} row{r}",
                     value,
-                    (_is_visible(r, c, idx_lengths) and not self.hidden_index),
+                    (_is_visible(r, c, idx_lengths) and not self.hide_index_),
                     id=f"level{c}_row{r}",
                     attributes=(
                         f'rowspan="{idx_lengths.get((c, r), 0)}"'
diff --git a/pandas/tests/io/formats/style/test_style.py b/pandas/tests/io/formats/style/test_style.py
index 326f22845521d..281199c2c482b 100644
--- a/pandas/tests/io/formats/style/test_style.py
+++ b/pandas/tests/io/formats/style/test_style.py
@@ -85,7 +85,7 @@ def test_copy(self, do_changes, do_render):
                 [{"selector": "th", "props": [("foo", "bar")]}]
             )
             self.styler.set_table_attributes('class="foo" data-bar')
-            self.styler.hidden_index = not self.styler.hidden_index
+            self.styler.hide_index_ = not self.styler.hide_index_
             self.styler.hide_columns("A")
             classes = DataFrame(
                 [["favorite-val red", ""], [None, "blue my-val"]],
@@ -156,7 +156,7 @@ def test_copy(self, do_changes, do_render):
             "table_styles",
             "table_attributes",
             "cell_ids",
-            "hidden_index",
+            "hide_index_",
             "hidden_columns",
             "cell_context",
         ]
@@ -181,7 +181,7 @@ def test_clear(self):
         assert len(s._todo) > 0
         assert s.tooltips
         assert len(s.cell_context) > 0
-        assert s.hidden_index is True
+        assert s.hide_index_ is True
         assert len(s.hidden_columns) > 0
 
         s = s._compute()
@@ -195,7 +195,7 @@ def test_clear(self):
         assert len(s._todo) == 0
         assert not s.tooltips
         assert len(s.cell_context) == 0
-        assert s.hidden_index is False
+        assert s.hide_index_ is False
         assert len(s.hidden_columns) == 0
 
     def test_render(self):

From 4d9626d49528a53570a4dead20cd3bdc3d11b2e3 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Thu, 20 May 2021 10:17:40 +0200
Subject: [PATCH 12/16] nomenclature: comments

---
 pandas/io/formats/style_render.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/io/formats/style_render.py b/pandas/io/formats/style_render.py
index ba965b49afab4..f1a8317ca10c7 100644
--- a/pandas/io/formats/style_render.py
+++ b/pandas/io/formats/style_render.py
@@ -96,9 +96,9 @@ def __init__(
         self.cell_ids = cell_ids
 
         # add rendering variables
-        self.hide_index_: bool = False
+        self.hide_index_: bool = False  # bools for hiding col/row headers
         self.hide_columns_: bool = False
-        self.hidden_rows: Sequence[int] = []
+        self.hidden_rows: Sequence[int] = []  # sequence for specific hidden rows/cols
         self.hidden_columns: Sequence[int] = []
         self.ctx: DefaultDict[tuple[int, int], CSSList] = defaultdict(list)
         self.cell_context: DefaultDict[tuple[int, int], str] = defaultdict(str)

From c6c108646c4c5f6169a433d15e45e79157ef9161 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Sat, 22 May 2021 19:16:07 +0200
Subject: [PATCH 13/16] merge upstream master

---
 pandas/tests/io/formats/style/test_style.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/io/formats/style/test_style.py b/pandas/tests/io/formats/style/test_style.py
index b145a4831c9f2..342aaed9abe70 100644
--- a/pandas/tests/io/formats/style/test_style.py
+++ b/pandas/tests/io/formats/style/test_style.py
@@ -1088,11 +1088,11 @@ def test_mi_sparse_column_names(self):
         assert head == expected
 
     def test_hide_column_headers(self):
-        ctx = self.styler.hide_columns()._translate()
+        ctx = self.styler.hide_columns()._translate(True, True)
         assert len(ctx["head"]) == 0  # no header entries with an unnamed index
 
         self.df.index.name = "some_name"
-        ctx = self.df.style.hide_columns()._translate()
+        ctx = self.df.style.hide_columns()._translate(True, True)
         assert len(ctx["head"]) == 1  # only a single row for index names: no col heads
 
     def test_hide_single_index(self):

From 16a4da3b3bc668e06e85ba1228e0c69252838203 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Sun, 23 May 2021 22:41:10 +0200
Subject: [PATCH 14/16] fix spelling

---
 pandas/io/formats/style.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index 9f6400c100029..ef743fd321042 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -1208,7 +1208,7 @@ def hide_columns(self, subset: Subset | None = None) -> Styler:
 
         Examples
         --------
-        Simple application hiding specific rows:
+        Simple application hiding specific columns:
 
         >>> df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], columns=["a", "b", "c"])
         >>> df.style.hide_columns(["a", "b"])

From ec5817c2d71503da3c2399994b5affd02360a64f Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Mon, 24 May 2021 17:18:29 +0200
Subject: [PATCH 15/16] adjust to_lext components after recent merge

---
 pandas/io/formats/style.py        | 2 +-
 pandas/io/formats/style_render.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/io/formats/style.py b/pandas/io/formats/style.py
index b6fc93243d219..bdb43792351a6 100644
--- a/pandas/io/formats/style.py
+++ b/pandas/io/formats/style.py
@@ -680,7 +680,7 @@ def to_latex(
             self.data.columns = RangeIndex(stop=len(self.data.columns))
             numeric_cols = self.data._get_numeric_data().columns.to_list()
             self.data.columns = _original_columns
-            column_format = "" if self.hidden_index else "l" * self.data.index.nlevels
+            column_format = "" if self.hide_index_ else "l" * self.data.index.nlevels
             for ci, _ in enumerate(self.data.columns):
                 if ci not in self.hidden_columns:
                     column_format += (
diff --git a/pandas/io/formats/style_render.py b/pandas/io/formats/style_render.py
index 1bbb2945cddcc..fd961c8e0da1b 100644
--- a/pandas/io/formats/style_render.py
+++ b/pandas/io/formats/style_render.py
@@ -429,7 +429,7 @@ def _translate_latex(self, d: dict) -> None:
         d["head"] = [[col for col in row if col["is_visible"]] for row in d["head"]]
         body = []
         for r, row in enumerate(d["body"]):
-            if self.hidden_index:
+            if self.hide_index_:
                 row_body_headers = []
             else:
                 row_body_headers = [

From 0921804c89489b115bf8dc94cf97c89e0dccb448 Mon Sep 17 00:00:00 2001
From: "JHM Darbyshire (iMac)" <attack68@users.noreply.github.com>
Date: Sat, 5 Jun 2021 07:41:54 +0200
Subject: [PATCH 16/16] merge upstream master

---
 pandas/io/formats/style_render.py | 50 +++++++++++++++----------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/pandas/io/formats/style_render.py b/pandas/io/formats/style_render.py
index fe9d4a5a821ab..514597d27a92b 100644
--- a/pandas/io/formats/style_render.py
+++ b/pandas/io/formats/style_render.py
@@ -315,34 +315,34 @@ def _translate_header(
                     )
                 ]
 
-            if clabels:
-                column_headers = [
-                    _element(
-                        "th",
-                        f"{col_heading_class} level{r} col{c}",
-                        value,
-                        _is_visible(c, r, col_lengths),
-                        attributes=(
-                            f'colspan="{col_lengths.get((r, c), 0)}"'
-                            if col_lengths.get((r, c), 0) > 1
-                            else ""
-                        ),
-                    )
-                    for c, value in enumerate(clabels[r])
-                ]
-
-                if len(self.data.columns) > max_cols:
-                    # add an extra column with `...` value to indicate trimming
-                    column_headers.append(
+                if clabels:
+                    column_headers = [
                         _element(
                             "th",
-                            f"{col_heading_class} level{r} {trimmed_col_class}",
-                            "...",
-                            True,
-                            attributes="",
+                            f"{col_heading_class} level{r} col{c}",
+                            value,
+                            _is_visible(c, r, col_lengths),
+                            attributes=(
+                                f'colspan="{col_lengths.get((r, c), 0)}"'
+                                if col_lengths.get((r, c), 0) > 1
+                                else ""
+                            ),
                         )
-                    )
-                head.append(index_blanks + column_name + column_headers)
+                        for c, value in enumerate(clabels[r])
+                    ]
+
+                    if len(self.data.columns) > max_cols:
+                        # add an extra column with `...` value to indicate trimming
+                        column_headers.append(
+                            _element(
+                                "th",
+                                f"{col_heading_class} level{r} {trimmed_col_class}",
+                                "...",
+                                True,
+                                attributes="",
+                            )
+                        )
+                    head.append(index_blanks + column_name + column_headers)
 
         # 2) index names
         if (