With numeric values within a table’s body cells, we can perform number-based formatting so that the targeted values are rendered with a higher consideration for tabular presentation. Furthermore, there is finer control over numeric formatting with the following options:
decimals: choice of the number of decimal places, option to drop trailing zeros, and a choice of the decimal symbol
digit grouping separators: options to enable/disable digit separators and provide a choice of separator symbol
scaling: we can choose to scale targeted values by a multiplier value
large-number suffixing: larger figures (thousands, millions, etc.) can be autoscaled and decorated with the appropriate suffixes
pattern: option to use a text pattern for decoration of the formatted values
locale-based formatting: providing a locale ID will result in number formatting specific to the chosen locale
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.
decimals:int=2
The decimals values corresponds to the exact number of decimal places to use. A value such as 2.34 can, for example, be formatted with 0 decimal places and it would result in "2". With 4 decimal places, the formatted value becomes "2.3400". The trailing zeros can be removed with drop_trailing_zeros=True. If you always need decimals = 0, the fmt_integer() method should be considered.
n_sigfig:int | None=None
A option to format numbers to n significant figures. By default, this is None and thus number values will be formatted according to the number of decimal places set via decimals. If opting to format according to the rules of significant figures, n_sigfig must be a number greater than or equal to 1. Any values passed to the decimals and drop_trailing_zeros arguments will be ignored.
drop_trailing_zeros:bool=False
A boolean value that allows for removal of trailing zeros (those redundant zeros after the decimal mark).
drop_trailing_dec_mark:bool=True
A boolean value that determines whether decimal marks should always appear even if there are no decimal digits to display after formatting (e.g., 23 becomes 23. if False). By default trailing decimal marks are not shown.
use_seps:bool=True
The use_seps option allows for the use of digit group separators. The type of digit group separator is set by sep_mark and overridden if a locale ID is provided to locale. This setting is True by default.
scale_by:float=1
All numeric values will be multiplied by the scale_by value before undergoing formatting. Since the default value is 1, no values will be changed unless a different multiplier value is supplied.
compact:bool=False
A boolean value that allows for compact formatting of numeric values. Values will be scaled and decorated with the appropriate suffixes (e.g., 1230 becomes 1.23K, and 1230000 becomes 1.23M). The compact option is False by default.
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.
sep_mark:str=','
The string to use as a separator between groups of digits. For example, using sep_mark="," with a value of 1000 would result in a formatted value of "1,000". This argument is ignored if a locale is supplied (i.e., is not None).
dec_mark:str='.'
The string to be used as the decimal mark. For example, using dec_mark="," with the value 0.152 would result in a formatted value of "0,152"). This argument is ignored if a locale is supplied (i.e., is not None).
force_sign:bool=False
Should the positive sign be shown for positive values (effectively showing a sign for all values except zero)? If so, use True for this option. The default is False, where only negative numbers will display a minus sign.
locale:str | None=None
An optional locale identifier that can be used for formatting values according the locale’s rules. Examples include "en" for English (United States) and "fr" for French (France).
The GT object is returned. This is the same object that the method is called on so that we can facilitate method chaining.
Adapting output to a specific locale
This formatting method can adapt outputs according to a provided locale value. Examples include "en" for English (United States) and "fr" for French (France). The use of a valid locale ID here means separator and decimal marks will be correct for the given locale. Should any values be provided in sep_mark or dec_mark, they will be overridden by the locale’s preferred values.
Note that a locale value provided here will override any global locale setting performed in GT()’s own locale argument (it is settable there as a value received by all other methods that have a locale argument).
Examples
Let’s use the exibble dataset to create a table. With the fmt_number() method, we’ll format the num column to have three decimal places (with decimals=3) and omit the use of digit separators (with use_seps=False).
from great_tables import GT, exibble( GT(exibble) .fmt_number(columns="num", decimals=3, use_seps=False))
num
char
fctr
date
time
datetime
currency
row
group
0.111
apricot
one
2015-01-15
13:35
2018-01-01 02:22
49.95
row_1
grp_a
2.222
banana
two
2015-02-15
14:40
2018-02-02 14:33
17.95
row_2
grp_a
33.330
coconut
three
2015-03-15
15:45
2018-03-03 03:44
1.39
row_3
grp_a
444.400
durian
four
2015-04-15
16:50
2018-04-04 15:55
65100.0
row_4
grp_a
5550.000
five
2015-05-15
17:55
2018-05-05 04:00
1325.81
row_5
grp_b
fig
six
2015-06-15
2018-06-06 16:11
13.255
row_6
grp_b
777000.000
grapefruit
seven
19:10
2018-07-07 05:22
row_7
grp_b
8880000.000
honeydew
eight
2015-08-15
20:20
0.44
row_8
grp_b
See Also
The fmt_integer() method might be more useful if you really need to format numeric values to appear as integers (i.e., no decimals will be shown and input values are rounded as necessary). Need to do numeric formatting on a value or list of values? Take a look at the functional version of this method: val_fmt_number().