pandas.io.formats.style.Styler.format_index_names#

Styler.format_index_names(formatter=None, axis=0, level=None, na_rep=None, precision=None, decimal='.', thousands=None, escape=None, hyperlinks=None)[source]#

Format the text display value of index names or column names.

Added in version 3.0.

Parameters:

formatterstr, callable, dict or None: Object to define how values are displayed. See notes.
axis{0, “index”, 1, “columns”}: Whether to apply the formatter to the index or column headers.
levelint, str, list: The level(s) over which to apply the generic formatter.
na_repstr, optional: Representation for missing values. If na_rep is None, no special formatting is applied.
precisionint, optional: Floating point precision to use for display purposes, if not determined by the specified formatter.
decimalstr, default “.”: Character used as decimal separator for floats, complex and integers.
thousandsstr, optional, default None: Character used as thousands separator for floats, complex and integers.
escapestr, optional: Use ‘html’ to replace the characters &, <, >, ', and " in cell display string with HTML-safe sequences. Use ‘latex’ to replace the characters &, %, $, #, _, {, }, ~, ^, and \ in the cell display string with LaTeX-safe sequences. Escaping is done before formatter.
hyperlinks{“html”, “latex”}, optional: Convert string patterns containing https://, http://, ftp:// or www. to HTML <a> tags as clickable URL hyperlinks if “html”, or LaTeX href commands if “latex”.

Returns:

Styler: Returns itself for chaining.

Raises:

ValueError: If the formatter is a string and the dtypes are incompatible.

See also

Styler.format_index: Format the text display value of index labels or column headers.

Notes

This method has a similar signature to Styler.format_index(). Since names are generally label based, and often not numeric, the typical features expected to be more frequently used here are escape and hyperlinks.

Warning

Styler.format_index_names is ignored when using the output format Styler.to_excel, since Excel and Python have inherently different formatting structures.

Examples

>>> df = pd.DataFrame(
...     [[1, 2], [3, 4]],
...     index=pd.Index(["a", "b"], name="idx"),
... )
>>> df  
     0  1
idx
a    1  2
b    3  4
>>> df.style.format_index_names(lambda x: x.upper(), axis=0)  
     0  1
IDX
a    1  2
b    3  4