pandas.io.formats.style.Styler.concat#

Styler.concat(other)[source]#

Append another Styler to combine the output into a single table.

New in version 1.5.0.

Parameters
otherStyler

The other Styler object which has already been styled and formatted. The data for this Styler must have the same columns as the original, and the number of index levels must also be the same to render correctly.

Returns
selfStyler

Notes

The purpose of this method is to extend existing styled dataframes with other metrics that may be useful but may not conform to the original’s structure. For example adding a sub total row, or displaying metrics such as means, variance or counts.

Styles that are applied using the apply, applymap, apply_index and applymap_index, and formatting applied with format and format_index will be preserved.

Warning

Only the output methods to_html, to_string and to_latex currently work with concatenated Stylers.

Other output methods, including to_excel, do not work with concatenated Stylers.

The following should be noted:

  • table_styles, table_attributes, caption and uuid are all inherited from the original Styler and not other.

  • hidden columns and hidden index levels will be inherited from the original Styler

  • css will be inherited from the original Styler, and the value of keys data, row_heading and row will be prepended with foot0_. If more concats are chained, their styles will be prepended with foot1_, ‘’foot_2’’, etc., and if a concatenated style have another concatanated style, the second style will be prepended with foot{parent}_foot{child}_.

A common use case is to concatenate user defined functions with DataFrame.agg or with described statistics via DataFrame.describe. See examples.

Examples

A common use case is adding totals rows, or otherwise, via methods calculated in DataFrame.agg.

>>> df = DataFrame([[4, 6], [1, 9], [3, 4], [5, 5], [9,6]],
...                columns=["Mike", "Jim"],
...                index=["Mon", "Tue", "Wed", "Thurs", "Fri"])
>>> styler = df.style.concat(df.agg(["sum"]).style)
../../_images/footer_simple.png

Since the concatenated object is a Styler the existing functionality can be used to conditionally format it as well as the original.

>>> descriptors = df.agg(["sum", "mean", lambda s: s.dtype])
>>> descriptors.index = ["Total", "Average", "dtype"]
>>> other = (descriptors.style
...          .highlight_max(axis=1, subset=(["Total", "Average"], slice(None)))
...          .format(subset=("Average", slice(None)), precision=2, decimal=",")
...          .applymap(lambda v: "font-weight: bold;"))
>>> styler = (df.style
...             .highlight_max(color="salmon")
...             .set_table_styles([{"selector": ".foot_row0",
...                                 "props": "border-top: 1px solid black;"}]))
>>> styler.concat(other)
../../_images/footer_extended.png

When other has fewer index levels than the original Styler it is possible to extend the index in other, with placeholder levels.

>>> df = DataFrame([[1], [2]], index=pd.MultiIndex.from_product([[0], [1, 2]]))
>>> descriptors = df.agg(["sum"])
>>> descriptors.index = pd.MultiIndex.from_product([[""], descriptors.index])
>>> df.style.concat(descriptors.style)