GT.fmt_partsper()

Format values as parts-per quantities.

Usage

GT.fmt_partsper(
    columns=None,
    rows=None,
    to_units="per-mille",
    symbol="auto",
    decimals=2,
    drop_trailing_zeros=False,
    drop_trailing_dec_mark=True,
    scale_values=True,
    use_seps=True,
    pattern="{x}",
    sep_mark=",",
    dec_mark=".",
    force_sign=False,
    incl_space="auto",
    locale=None
)

With numeric values in a gt table, we can format the values so that they are rendered as parts-per quantities (per mille, ppm, ppb, etc.). The following keywords are available for the to_units parameter:

"per-mille": Per mille (1 part in 1,000)
"per-myriad": Per myriad (1 part in 10,000)
"pcm": Per cent mille (1 part in 100,000)
"ppm": Parts per million (1 part in 1,000,000)
"ppb": Parts per billion (1 part in 1,000,000,000)
"ppt": Parts per trillion (1 part in 1,000,000,000,000)
"ppq": Parts per quadrillion (1 part in 1,000,000,000,000,000)

The function provides a lot of formatting control and we can use the following options:

custom symbol/units: override the automatic symbol or units display with a custom choice
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
value scaling toggle: choose to disable automatic value scaling in the situation that values are already scaled coming in (and just require the appropriate symbol or unit display)
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.
to_units: str = "per-mille": A keyword that signifies the desired output quantity. This can be any from the following set: "per-mille", "per-myriad", "pcm", "ppm", "ppb", "ppt", or "ppq".
symbol: str = "auto": The symbol/units to use for the quantity. By default, this is set to "auto" and the appropriate symbol will be chosen based on the to_units keyword and the output context. This can be changed by supplying a string (e.g., using symbol="ppbV" when to_units="ppb").
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.
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.
scale_values: bool = True: Should the values be scaled through multiplication according to the keyword set in to_units? By default this is True since the expectation is that normally values are proportions. Setting to False signifies that the values are already scaled and require only the appropriate symbol/units when formatted.
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.
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.
incl_space: str | bool = "auto": An option for whether to include a space between the value and the symbol/units. The default is "auto" which provides spacing dependent on the mark itself (symbols like ‰ get no space; text abbreviations like ppm get a space). This can be directly controlled by using either True or False.
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).

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.

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 a small dataset with proportional values and format them as parts-per-mille values.

from great_tables import GT
import pandas as pd

df = pd.DataFrame({"x": [0.001, 0.0001, 0.00001, 0.5, -0.005]})

GT(df).fmt_partsper(columns="x", to_units="per-mille")

x
1.00‰
0.10‰
0.01‰
500.00‰
−5.00‰

We can also format values as parts per million (ppm) using a Polars DataFrame:

import polars as pl
from great_tables import GT

df = pl.DataFrame({"x": [0.0000015, 0.00035, 0.0001]})

GT(df).fmt_partsper(columns="x", to_units="ppm")

x
1.50 ppm
350.00 ppm
100.00 ppm

If the values are already scaled (not proportions), set scale_values=False and use a custom symbol:

import polars as pl
from great_tables import GT

concentrations = pl.DataFrame({"gas": ["CO", "NO2", "O3"], "conc": [1.5, 35.0, 120.0]})

GT(concentrations).fmt_partsper(columns="conc", to_units="ppb", scale_values=False, symbol="ppbV")

gas	conc
CO	1.50 ppbV
NO2	35.00 ppbV
O3	120.00 ppbV

Parameters

Returns

Adapting Output To A Specific locale

Examples

Adapting Output To A Specific `locale`