isabella232 / pillar

Format columns with colour

pillar

pillar provides tools for styling columns of data, artfully using colour and unicode characters to guide the eye.

Due to limitations of GitHub's Markdown display, formatting cannot be shown in the README. The same content is available on https://pillar.r-lib.org/ with proper formatting.

Installation

# pillar is installed if you install the tidyverse package:
install.packages("tidyverse")

# Alternatively, install just pillar:
install.packages("pillar")

Usage

pillar is a developer-facing package that is not designed for end-users. It powers the print() and format() methods for tibbles. It also and defines generics and helpers that are useful for package authors who create custom vector classes (see https://github.com/krlmlr/awesome-vctrs#readme for examples) or custom table classes (like dbplyr or sf).

library(pillar)

x <- 123456789 * (10 ^ c(-3, -5, NA, -8, -10))
pillar(x)
#> <pillar>
#>       <dbl>
#> 123457.    
#>   1235.    
#>     NA     
#>      1.23  
#>      0.0123

tbl_format_setup(tibble::tibble(x))
#> <pillar_tbl_format_setup>
#> <tbl_format_header(setup)>
#> # A data frame: 5 × 1
#> <tbl_format_body(setup)>
#>             x
#>         <dbl>
#> 1 123457.    
#> 2   1235.    
#> 3     NA     
#> 4      1.23  
#> 5      0.0123
#> <tbl_format_footer(setup)>

Custom vector classes

The primary user of this package is tibble, which lets pillar do all the formatting work. Packages that implement a data type to be used in a tibble column can customize the display by implementing a pillar_shaft() method.

library(pillar)

percent <- vctrs::new_vctr(9:11 * 0.01, class = "percent")

pillar_shaft.percent <- function(x, ...) {
  fmt <- format(vctrs::vec_data(x) * 100)
  new_pillar_shaft_simple(paste0(fmt, " ", style_subtle("%")), align = "right")
}

pillar(percent)
#> <pillar>
#> <percent>
#>       9 %
#>      10 %
#>      11 %

See vignette("pillar", package = "vctrs") for details.

Custom table classes

pillar provides various extension points for customizing how a tibble-like class is printed.

tbl <- vctrs::new_data_frame(list(a = 1:3), class = c("my_tbl", "tbl"))

tbl_sum.my_tbl <- function(x, ...) {
  c("Hello" = "world!")
}

tbl
#> # Hello: world!
#>       a
#>   <int>
#> 1     1
#> 2     2
#> 3     3

See vignette("extending", package = "pillar") for a walkthrough of the options.

---

Code of Conduct

Please note that the pillar project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.