Styler.applymap_index(func, axis=0, level=None, **kwargs)[source]

Apply a CSS-styling function to the index or column headers, elementwise.

Updates the HTML representation with the result.

New in version 1.4.0.


func should take a scalar and return a string.

axis{0, 1, “index”, “columns”}

The headers over which to apply the function.

levelint, str, list, optional

If index is MultiIndex the level(s) over which to apply the function.


Pass along to func.


See also


Apply a CSS-styling function to headers level-wise.


Apply a CSS-styling function column-wise, row-wise, or table-wise.


Apply a CSS-styling function elementwise.


Each input to func will be an index value, if an Index, or a level value of a MultiIndex. The output of func should be CSS styles as a string, in the format ‘attribute: value; attribute2: value2; …’ or, if nothing is to be applied to that element, an empty string or None.


Basic usage to conditionally highlight values in the index.

>>> df = pd.DataFrame([[1,2], [3,4]], index=["A", "B"])
>>> def color_b(s):
...     return "background-color: yellow;" if v == "B" else None

Selectively applying to specific levels of MultiIndex columns.

>>> midx = pd.MultiIndex.from_product([['ix', 'jy'], [0, 1], ['x3', 'z4']])
>>> df = pd.DataFrame([np.arange(8)], columns=midx)
>>> def highlight_x(v):
...     return "background-color: yellow;" if "x" in v else None
>>>, axis="columns", level=[0, 2])