GT.grand_summary_rows

GT.grand_summary_rows(
    self,
    fns,
    fmt=None,
    columns=None,
    side='bottom',
    missing_text='---',
)

Add grand summary rows to the table.

Add grand summary rows by using the table data and any suitable aggregation functions. With grand summary rows, all of the available data in the gt table is incorporated (regardless of whether some of the data are part of row groups). Multiple grand summary rows can be added via expressions given to fns. You can selectively format the values in the resulting grand summary cells by use of formatting expressions from the vals.fmt_* class of functions.

Parameters

fns : dict[str, PlExpr] | dict[str, Callable[[TblData], Any]]

A dictionary mapping row labels to aggregation expressions. Can be either Polars expressions or callable functions that take the entire DataFrame and return aggregated results. Each key becomes the label for a grand summary row.

fmt : FormatFn | None = None

A formatting function from the vals.fmt_* family (e.g., vals.fmt_number, vals.fmt_currency) to apply to the summary row values. If None, no formatting is applied.

columns : SelectExpr = None

Currently, this function does not support selection by columns. If you would like to choose which columns to summarize, you can select columns within the functions given to fns=. See examples below for more explicit cases.

side : Literal['bottom', 'top'] = 'bottom'

Should the grand summary rows be placed at the "bottom" (the default) or the "top" of the table?

missing_text : str = '—'

The text to be used in summary cells with no data outputs.

Returns

: GT

The GT object is returned. This is the same object that the method is called on so that we can facilitate method chaining.

Examples

Let’s use a subset of the sp500 dataset to create a table with grand summary rows. We’ll calculate min, max, and mean values for the numeric columns. Notice the different approaches to selecting columns to apply the aggregations to: we can use polars selectors or select the columns directly.

import polars as pl
import polars.selectors as cs
from great_tables import GT, vals, style, loc
from great_tables.data import sp500

sp500_mini = (
    pl.from_pandas(sp500)
    .slice(0, 7)
    .drop(["volume", "adj_close"])
)

(
    GT(sp500_mini, rowname_col="date")
    .grand_summary_rows(
        fns={
            "Minimum": pl.min("open", "high", "low", "close"),
            "Maximum": pl.col("open", "high", "low", "close").max(),
            "Average": cs.numeric().mean(),
        },
        fmt=vals.fmt_currency,
    )
    .tab_style(
        style=[
            style.text(color="crimson"),
            style.fill(color="lightgray"),
        ],
        locations=loc.grand_summary(),
    )
)

	open	high	low	close
2015-12-31	2060.5901	2062.54	2043.62	2043.9399
2015-12-30	2077.3401	2077.3401	2061.97	2063.3601
2015-12-29	2060.54	2081.5601	2060.54	2078.3601
2015-12-28	2057.77	2057.77	2044.2	2056.5
2015-12-24	2063.52	2067.3601	2058.73	2060.99
2015-12-23	2042.2	2064.73	2042.2	2064.29
2015-12-22	2023.15	2042.74	2020.49	2038.97
Minimum	$2,023.15	$2,042.74	$2,020.49	$2,038.97
Maximum	$2,077.34	$2,081.56	$2,061.97	$2,078.36
Average	$2,055.02	$2,064.86	$2,047.39	$2,058.06

We can also use custom callable functions to create more complex summary calculations. Notice here that grand summary rows can be placed at the top of the table and formatted with currency notation, by passing a formatter from the vals.fmt_* class of functions.

from great_tables import GT, style, loc, vals
from great_tables.data import gtcars

def pd_median(df):
    return df.median(numeric_only=True)


(
    GT(
        gtcars[["mfr", "model", "hp", "trq", "mpg_c"]].head(6),
        rowname_col="model",
    )
    .fmt_integer(columns=["hp", "trq", "mpg_c"])
    .grand_summary_rows(
        fns={
            "Min": lambda df: df.min(numeric_only=True),
            "Max": lambda df: df.max(numeric_only=True),
            "Median": pd_median,
        },
        side="top",
        fmt=vals.fmt_integer,
    )
    .tab_style(
        style=[style.text(color="crimson", weight="bold"), style.fill(color="lightgray")],
        locations=loc.grand_summary_stub(),
    )
)

	mfr	hp	trq	mpg_c
Min	---	553	398	11
Max	---	661	561	16
Median	---	580	474	13
GT	Ford	647	550	11
458 Speciale	Ferrari	597	398	13
458 Spider	Ferrari	562	398	13
458 Italia	Ferrari	562	398	13
488 GTB	Ferrari	661	561	15
California	Ferrari	553	557	16