The text_case_when() function

Use metro to create a gt table. In the connect_rer column, perform a count of pattern matches with stringr::str_count() and determine which cells have 1, 2, or 3 matched patterns. For each of these cases, provide descriptive replacement text. Here, we use a .default to replace the non-matched cases with an empty string.

metro |>
  dplyr::arrange(desc(passengers)) |>
  dplyr::select(name, lines, connect_rer) |>
  dplyr::slice_head(n = 10) |>
  gt() |>
  text_case_when(
    stringr::str_count(x, pattern = "[ABCDE]") == 1 ~ "One connection.",
    stringr::str_count(x, pattern = "[ABCDE]") == 2 ~ "Two connections.",
    stringr::str_count(x, pattern = "[ABCDE]") == 3 ~ "Three connections.",
    .default = "", .locations = cells_body(columns = connect_rer)
  ) |>
  cols_label(
    name = "Station",
    lines = "Lines Serviced",
    connect_rer = "RER Connections"
  )

Station	Lines Serviced	RER Connections
Gare du Nord	4, 5	Three connections.
Saint-Lazare	3, 12, 13, 14	One connection.
Gare de Lyon	1, 14	Two connections.
Montparnasse—Bienvenüe	4, 6, 12, 13
Gare de l'Est	4, 5, 7	One connection.
Bibliothèque François Mitterrand	14	One connection.
République	3, 5, 8, 9, 11
Les Halles	4	Three connections.
La Défense	1	One connection.
Châtelet	1, 4, 7, 11, 14	Three connections.