R glue glue 格式化并插入字符串

glue_data(
  .x,
  ...,
  .sep = "",
  .envir = parent.frame(),
  .open = "{",
  .close = "}",
  .na = "NA",
  .null = character(),
  .comment = "#",
  .literal = FALSE,
  .transformer = identity_transformer,
  .trim = TRUE
)

glue(
  ...,
  .sep = "",
  .envir = parent.frame(),
  .open = "{",
  .close = "}",
  .na = "NA",
  .null = character(),
  .comment = "#",
  .literal = FALSE,
  .transformer = identity_transformer,
  .trim = TRUE
)

https://www.python.org/dev/peps/pep-0498/ and https://www.python.org/dev/peps/pep-0257/ upon which this is based.

name <- "Fred"
age <- 50
anniversary <- as.Date("1991-10-12")
glue('My name is {name},',
  'my age next year is {age + 1},',
  'my anniversary is {format(anniversary, "%A, %B %d, %Y")}.')
#> My name is Fred,my age next year is 51,my anniversary is Saturday, October 12, 1991.

# single braces can be inserted by doubling them
glue("My name is {name}, not {{name}}.")
#> My name is Fred, not {name}.

# Named arguments can be used to assign temporary variables.
glue('My name is {name},',
  ' my age next year is {age + 1},',
  ' my anniversary is {format(anniversary, "%A, %B %d, %Y")}.',
  name = "Joe",
  age = 40,
  anniversary = as.Date("2001-10-12"))
#> My name is Joe, my age next year is 41, my anniversary is Friday, October 12, 2001.

# `glue()` can also be used in user defined functions
intro <- function(name, profession, country){
  glue("My name is {name}, a {profession}, from {country}")
}
intro("Shelmith", "Senior Data Analyst", "Kenya")
#> My name is Shelmith, a Senior Data Analyst, from Kenya
intro("Cate", "Data Scientist", "Kenya")
#> My name is Cate, a Data Scientist, from Kenya

# `glue_data()` is useful in magrittr pipes
if (require(magrittr)) {

mtcars %>% glue_data("{rownames(.)} has {hp} hp")

# Or within dplyr pipelines
if (require(dplyr)) {

head(iris) %>%
  mutate(description = glue("This {Species} has a petal length of {Petal.Length}"))

}}
#> Loading required package: magrittr
#> Loading required package: dplyr
#> 
#> Attaching package: ‘dplyr’
#> The following objects are masked from ‘package:stats’:
#> 
#>     filter, lag
#> The following objects are masked from ‘package:base’:
#> 
#>     intersect, setdiff, setequal, union
#>   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#> 1          5.1         3.5          1.4         0.2  setosa
#> 2          4.9         3.0          1.4         0.2  setosa
#> 3          4.7         3.2          1.3         0.2  setosa
#> 4          4.6         3.1          1.5         0.2  setosa
#> 5          5.0         3.6          1.4         0.2  setosa
#> 6          5.4         3.9          1.7         0.4  setosa
#>                             description
#> 1 This setosa has a petal length of 1.4
#> 2 This setosa has a petal length of 1.4
#> 3 This setosa has a petal length of 1.3
#> 4 This setosa has a petal length of 1.5
#> 5 This setosa has a petal length of 1.4
#> 6 This setosa has a petal length of 1.7

# Alternative delimiters can also be used if needed
one <- "1"
glue("The value of $e^{2\\pi i}$ is $<<one>>$.", .open = "<<", .close = ">>")
#> The value of $e^{2\pi i}$ is $1$.