ENH: add kw level to Styler.hide_columns (#42914)

* add levels to hide_columns

* add levels to hide_columns

* add tests

* change levels to level (jreback)

* Update doc/source/whatsnew/v1.4.0.rst

Co-authored-by: JHM Darbyshire (iMac) <[email protected]>
Co-authored-by: Jeff Reback <[email protected]>

Author: attack68

doc/source/whatsnew/v1.4.0.rst

@@ -34,7 +34,7 @@ Other enhancements
 - :meth:`Series.sample`, :meth:`DataFrame.sample`, and :meth:`.GroupBy.sample` now accept a ``np.random.Generator`` as input to ``random_state``. A generator will be more performant, especially with ``replace=False`` (:issue:`38100`)
 -  Additional options added to :meth:`.Styler.bar` to control alignment and display, with keyword only arguments (:issue:`26070`, :issue:`36419`)
 - :meth:`Styler.bar` now validates the input argument ``width`` and ``height`` (:issue:`42511`)
-- Add keyword ``levels`` to :meth:`.Styler.hide_index` for optionally controlling hidden levels in a MultiIndex (:issue:`25475`)
+- Add keyword ``level`` to :meth:`.Styler.hide_index` and :meth:`.Styler.hide_columns` for optionally controlling hidden levels in a MultiIndex (:issue:`25475`)
 - :meth:`Series.ewm`, :meth:`DataFrame.ewm`, now support a ``method`` argument with a ``'table'`` option that performs the windowing operation over an entire :class:`DataFrame`. See :ref:`Window Overview <window.overview>` for performance and functional benefits (:issue:`42273`)
 - Added ``sparse_index`` and ``sparse_columns`` keyword arguments to :meth:`.Styler.to_html` (:issue:`41946`)
 - Added keyword argument ``environment`` to :meth:`.Styler.to_latex` also allowing a specific "longtable" entry with a separate jinja2 template (:issue:`41866`)

pandas/io/formats/style.py

@@ -32,6 +32,7 @@
 
 import pandas as pd
 from pandas import (
+    Index,
     IndexSlice,
     RangeIndex,
 )
@@ -1785,7 +1786,7 @@ def set_na_rep(self, na_rep: str) -> StylerRenderer:
     def hide_index(
         self,
         subset: Subset | None = None,
-        levels: Level | list[Level] | None = None,
+        level: Level | list[Level] | None = None,
     ) -> Styler:
         """
         Hide the entire index, or specific keys in the index from rendering.
@@ -1805,7 +1806,7 @@ def hide_index(
             A valid 1d input or single key along the index axis within
             `DataFrame.loc[<subset>, :]`, to limit ``data`` to *before* applying
             the function.
-        levels : int, str, list
+        level : int, str, list
             The level(s) to hide in a MultiIndex if hiding the entire index. Cannot be
             used simultaneously with ``subset``.
 
@@ -1862,7 +1863,7 @@ def hide_index(
 
         Hide a specific level:
 
-        >>> df.style.format("{:,.1f").hide_index(levels=1)  # doctest: +SKIP
+        >>> df.style.format("{:,.1f").hide_index(level=1)  # doctest: +SKIP
                              x                    y
                a      b      c      a      b      c
         x    0.1    0.0    0.4    1.3    0.6   -1.4
@@ -1872,27 +1873,11 @@ def hide_index(
             -0.6    1.2    1.8    1.9    0.3    0.3
              0.8    0.5   -0.3    1.2    2.2   -0.8
         """
-        if levels is not None and subset is not None:
-            raise ValueError("`subset` and `levels` cannot be passed simultaneously")
+        if level is not None and subset is not None:
+            raise ValueError("`subset` and `level` cannot be passed simultaneously")
 
         if subset is None:
-            if levels is None:
-                levels_: list[Level] = list(range(self.index.nlevels))
-            elif isinstance(levels, int):
-                levels_ = [levels]
-            elif isinstance(levels, str):
-                levels_ = [self.index._get_level_number(levels)]
-            elif isinstance(levels, list):
-                levels_ = [
-                    self.index._get_level_number(lev)
-                    if not isinstance(lev, int)
-                    else lev
-                    for lev in levels
-                ]
-            else:
-                raise ValueError(
-                    "`levels` must be of type `int`, `str` or list of such"
-                )
+            levels_ = _refactor_levels(level, self.index)
             self.hide_index_ = [
                 True if lev in levels_ else False for lev in range(self.index.nlevels)
             ]
@@ -1906,14 +1891,18 @@ def hide_index(
             self.hidden_rows = hrows  # type: ignore[assignment]
         return self
 
-    def hide_columns(self, subset: Subset | None = None) -> Styler:
+    def hide_columns(
+        self,
+        subset: Subset | None = None,
+        level: Level | list[Level] | None = None,
+    ) -> Styler:
         """
         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 ``subset`` is ``None`` then the entire column headers row, or
+            specific levels, 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.
 
@@ -1925,6 +1914,11 @@ def hide_columns(self, subset: Subset | None = None) -> Styler:
             A valid 1d input or single key along the columns axis within
             `DataFrame.loc[:, <subset>]`, to limit ``data`` to *before* applying
             the function.
+        level : int, str, list
+            The level(s) to hide in a MultiIndex if hiding the entire column headers
+            row. Cannot be used simultaneously with ``subset``.
+
+            .. versionadded:: 1.4.0
 
         Returns
         -------
@@ -1979,9 +1973,26 @@ def hide_columns(self, subset: Subset | None = None) -> Styler:
         y   a    1.0   -1.2
             b    1.2    0.3
             c    0.5    2.2
+
+        Hide a specific level:
+
+        >>> df.style.format("{:.1f}").hide_columns(level=1)  # doctest: +SKIP
+                   x                    y
+        x   a    0.1    0.0    0.4    1.3    0.6   -1.4
+            b    0.7    1.0    1.3    1.5   -0.0   -0.2
+            c    1.4   -0.8    1.6   -0.2   -0.4   -0.3
+        y   a    0.4    1.0   -0.2   -0.8   -1.2    1.1
+            b   -0.6    1.2    1.8    1.9    0.3    0.3
+            c    0.8    0.5   -0.3    1.2    2.2   -0.8
         """
+        if level is not None and subset is not None:
+            raise ValueError("`subset` and `level` cannot be passed simultaneously")
+
         if subset is None:
-            self.hide_columns_ = True
+            levels_ = _refactor_levels(level, self.columns)
+            self.hide_columns_ = [
+                True if lev in levels_ else False for lev in range(self.columns.nlevels)
+            ]
         else:
             subset_ = IndexSlice[:, subset]  # new var so mypy reads not Optional
             subset = non_reducing_slice(subset_)
@@ -3172,3 +3183,37 @@ def css_calc(x, left: float, right: float, align: str):
             index=data.index,
             columns=data.columns,
         )
+
+
+def _refactor_levels(
+    level: Level | list[Level] | None,
+    obj: Index,
+) -> list[Level]:
+    """
+    Returns a consistent levels arg for use in ``hide_index`` or ``hide_columns``.
+
+    Parameters
+    ----------
+    level : int, str, list
+        Original ``level`` arg supplied to above methods.
+    obj:
+        Either ``self.index`` or ``self.columns``
+
+    Returns
+    -------
+    list : refactored arg with a list of levels to hide
+    """
+    if level is None:
+        levels_: list[Level] = list(range(obj.nlevels))
+    elif isinstance(level, int):
+        levels_ = [level]
+    elif isinstance(level, str):
+        levels_ = [obj._get_level_number(level)]
+    elif isinstance(level, list):
+        levels_ = [
+            obj._get_level_number(lev) if not isinstance(lev, int) else lev
+            for lev in level
+        ]
+    else:
+        raise ValueError("`level` must be of type `int`, `str` or list of such")
+    return levels_

pandas/io/formats/style_render.py

@@ -98,7 +98,7 @@ def __init__(
 
         # add rendering variables
         self.hide_index_: list = [False] * self.index.nlevels
-        self.hide_columns_: bool = False
+        self.hide_columns_: list = [False] * self.columns.nlevels
         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)
@@ -303,8 +303,10 @@ def _translate_header(
 
         head = []
         # 1) column headers
-        if not self.hide_columns_:
-            for r in range(self.data.columns.nlevels):
+        for r, hide in enumerate(self.hide_columns_):
+            if hide:
+                continue
+            else:
                 # number of index blanks is governed by number of hidden index levels
                 index_blanks = [_element("th", blank_class, blank_value, True)] * (
                     self.index.nlevels - sum(self.hide_index_) - 1
@@ -354,7 +356,7 @@ def _translate_header(
             self.data.index.names
             and com.any_not_none(*self.data.index.names)
             and not all(self.hide_index_)
-            and not self.hide_columns_
+            and not all(self.hide_columns_)
         ):
             index_names = [
                 _element(

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

@@ -261,19 +261,19 @@ def test_clear(mi_styler_comp):
 
 
 def test_hide_raises(mi_styler):
-    msg = "`subset` and `levels` cannot be passed simultaneously"
+    msg = "`subset` and `level` cannot be passed simultaneously"
     with pytest.raises(ValueError, match=msg):
-        mi_styler.hide_index(subset="something", levels="something else")
+        mi_styler.hide_index(subset="something", level="something else")
 
-    msg = "`levels` must be of type `int`, `str` or list of such"
+    msg = "`level` must be of type `int`, `str` or list of such"
     with pytest.raises(ValueError, match=msg):
-        mi_styler.hide_index(levels={"bad": 1, "type": 2})
+        mi_styler.hide_index(level={"bad": 1, "type": 2})
 
 
-@pytest.mark.parametrize("levels", [1, "one", [1], ["one"]])
-def test_hide_level(mi_styler, levels):
+@pytest.mark.parametrize("level", [1, "one", [1], ["one"]])
+def test_hide_index_level(mi_styler, level):
     mi_styler.index.names, mi_styler.columns.names = ["zero", "one"], ["zero", "one"]
-    ctx = mi_styler.hide_index(levels=levels)._translate(False, True)
+    ctx = mi_styler.hide_index(level=level)._translate(False, True)
     assert len(ctx["head"][0]) == 3
     assert len(ctx["head"][1]) == 3
     assert len(ctx["head"][2]) == 4
@@ -286,6 +286,16 @@ def test_hide_level(mi_styler, levels):
     assert not ctx["body"][1][1]["is_visible"]
 
 
+@pytest.mark.parametrize("level", [1, "one", [1], ["one"]])
+@pytest.mark.parametrize("names", [True, False])
+def test_hide_columns_level(mi_styler, level, names):
+    mi_styler.columns.names = ["zero", "one"]
+    if names:
+        mi_styler.index.names = ["zero", "one"]
+    ctx = mi_styler.hide_columns(level=level)._translate(True, False)
+    assert len(ctx["head"]) == (2 if names else 1)
+
+
 class TestStyler:
     def setup_method(self, method):
         np.random.seed(24)