gt-cols_label_with – The gt package

The `cols_label_with()` function

Use a subset of the sp500 dataset to create a gt table. We want all the column labels to be entirely capitalized versions of the default labels but, instead of using cols_label() and rewriting each label manually in capital letters we can use cols_label_with() and instruct it to apply the toupper() function to all column labels.

sp500 |>
  dplyr::filter(
    date >= "2015-12-01" &
      date <= "2015-12-15"
  ) |>
  dplyr::select(-c(adj_close, volume)) |>
  gt() |>
  cols_label_with(fn = toupper)

DATE	OPEN	HIGH	LOW	CLOSE
2015-12-15	2025.55	2053.87	2025.55	2043.41
2015-12-14	2013.37	2022.92	1993.26	2021.94
2015-12-11	2047.27	2047.27	2008.80	2012.37
2015-12-10	2047.93	2067.65	2045.67	2052.23
2015-12-09	2061.17	2080.33	2036.53	2047.62
2015-12-08	2073.39	2073.85	2052.32	2063.59
2015-12-07	2090.42	2090.42	2066.78	2077.07
2015-12-04	2051.24	2093.84	2051.24	2091.69
2015-12-03	2080.71	2085.00	2042.35	2049.62
2015-12-02	2101.71	2104.27	2077.11	2079.51
2015-12-01	2082.93	2103.37	2082.93	2102.63

Use the countrypops dataset to create a gt table. To improve the presentation of the table, we are again going to change the default column labels via function calls supplied within cols_label_with(). We can, if we prefer, apply multiple types of column label changes in sequence with multiple calls of cols_label_with(). Here, we use the make_clean_names() functions from the janitor package and follow up with the removal of a numeral with gsub().

countrypops |>
  dplyr::filter(year == 2021) |>
  dplyr::filter(grepl("^C", country_code_3)) |>
  dplyr::select(-country_code_2, -year) |>
  head(8) |>
  gt() |>
  cols_move_to_start(columns = country_code_3) |>
  fmt_integer(columns = population) |>
  cols_label_with(
    fn = ~ janitor::make_clean_names(., case = "title")
  ) |>
  cols_label_with(
    fn = ~ gsub("[0-9]", "", .)
  )

Country Code	Country Name	Population
CAF	Central African Republic	5,457,154
CAN	Canada	38,226,498
CHE	Switzerland	8,703,405
CHL	Chile	19,493,184
CHN	China	1,412,360,000
CIV	Cote d'Ivoire	27,478,249
CMR	Cameroon	27,198,628
COD	Congo (DRC)	95,894,118

We can make a svelte gt table with the pizzaplace dataset. There are ways to use one instance of cols_label_with() with multiple functions called on the column labels. In the example, we use an anonymous function call (with the function(x) { ... } construction) to perform multiple mutations of x (the vector of column labels). We can even use the md() helper function with that to signal to gt that the column label should be interpreted as Markdown text.

pizzaplace |>
  dplyr::mutate(month = substr(date, 6, 7)) |>
  dplyr::count(month, name = "pizze_vendute") |>
  dplyr::mutate(frazione_della_quota = pizze_vendute / 4000) |>
  dplyr::mutate(date = paste0("2015/", month, "/01")) |>
  dplyr::select(-month) |>
  gt(rowname_col = "date") |>
  fmt_date(date, date_style = "month", locale = "it") |>
  fmt_percent(columns = frazione_della_quota) |>
  fmt_integer(columns = pizze_vendute) |>
  cols_width(everything() ~ px(100)) |>
  cols_label_with(
    fn = function(x) {
      janitor::make_clean_names(x, case = "title") |>
        toupper() |>
        stringr::str_replace_all("^|$", "**") |>
        md()
    }
  )

	PIZZE VENDUTE	FRAZIONE DELLA QUOTA
gennaio	4,232	105.80%
febbraio	3,961	99.02%
marzo	4,261	106.53%
aprile	4,151	103.77%
maggio	4,328	108.20%
giugno	4,107	102.68%
luglio	4,392	109.80%
agosto	4,168	104.20%
settembre	3,890	97.25%
ottobre	3,883	97.08%
novembre	4,266	106.65%
dicembre	3,935	98.38%

The cols_label_with() function

The `cols_label_with()` function