Format True and False values
GT.fmt_tf(
columns=None,
rows=None,
tf_style="true-false",
pattern="{x}",
true_val=None,
false_val=None,
na_val=None,
colors=None
)
There can be times where boolean values are useful in a display table. You might want to express a ‘yes’ or ‘no’, a ‘true’ or ‘false’, or, perhaps use pairings of complementary symbols that make sense in a table. The fmt_tf() method has a set of tf_style= presets that can be used to quickly map True/False values to strings, or, symbols like up/down or left/right arrows and open/closed shapes.
While the presets are nice, you can provide your own mappings through the true_val= and false_val= arguments. For extra customization, you can also apply color to the individual True, False, and NA mappings. Just supply a list of colors (up to a length of 3) to the colors= argument.
Parameters
columns: SelectExpr = None-
The columns to target. Can either be a single column name or a series of column names provided in a list.
rows: int | list[int] | None = None-
In conjunction with columns=, we can specify which of their rows should undergo formatting. The default is all rows, resulting in all rows in targeted columns being formatted. Alternatively, we can supply a list of row indices.
tf_style: str = "true-false"-
The True/False mapping style to use. By default this is the short name "true-false" which corresponds to the words "true" and "false". Two other tf_style= values produce words: "yes-no" and "up-down". The remaining options involve pairs of symbols (e.g., "check-mark" displays a check mark for True and an ✗ symbol for False).
pattern: str = "{x}"-
A formatting pattern that allows for decoration of the formatted value. The formatted value is represented by the {x} (which can be used multiple times, if needed) and all other characters will be interpreted as string literals.
true_val: str | None = None-
While the choice of a tf_style= will typically supply the true_val= and false_val= text, we could override this and supply text for any True values. This doesn’t need to be used in conjunction with false_val=.
false_val: str | None = None-
While the choice of a tf_style= will typically supply the true_val= and false_val= text, we could override this and supply text for any False values. This doesn’t need to be used in conjunction with true_val=.
na_val: str | None = None-
None of the tf_style presets will replace any missing values encountered in the targeted cells. While we always have the option to use sub_missing() for NA replacement, we have the opportunity handle missing values here with the na_val= option. This is useful because we also have the means to add color to the na_val= text or symbol and doing that requires that a replacement value for NAs is specified here.
colors: list[str] | None = None-
Providing a list of color values to colors will progressively add color to the formatted result depending on the number of colors provided. With a single color, all formatted values will be in that color. Using two colors results in
True values being the first color, and False values receiving the second. With the three-color option, the final color will be given to any missing values replaced through na_val=.
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 small table containing opening and closing price data for the last few days in 2015. We added a boolean column (dir) where True indicates a price increase from opening to closing and False is the opposite. Using fmt_tf() generates up and down arrows in the dir column. We elect to use green upward arrows and red downward arrows (through the colors= option).
from great_tables import GT
from great_tables.data import sp500
import polars as pl
sp500_mini = (
pl.from_pandas(sp500)
.slice(0, 5)
.drop(["volume", "adj_close", "high", "low"])
.with_columns(dir = pl.col("close") > pl.col("open"))
)
(
GT(sp500_mini, rowname_col="date")
.fmt_tf(columns="dir", tf_style="arrows", colors=["green", "red"])
.fmt_currency(columns=["open", "close"])
.cols_label(
open="Opening",
close="Closing",
dir=""
)
)
|
Opening |
Closing |
|
| 2015-12-31 |
$2,060.59 |
$2,043.94 |
↓ |
| 2015-12-30 |
$2,077.34 |
$2,063.36 |
↓ |
| 2015-12-29 |
$2,060.54 |
$2,078.36 |
↑ |
| 2015-12-28 |
$2,057.77 |
$2,056.50 |
↓ |
| 2015-12-24 |
$2,063.52 |
$2,060.99 |
↓ |