Split up a string into pieces

Vectorised over string and pattern.

str_split(string, pattern, n = Inf, simplify = FALSE)

str_split_fixed(string, pattern, n)

str_split_n(string, pattern, n)

Arguments

string	Input vector. Either a character vector, or something coercible to one.
pattern	Pattern to look for. The default interpretation is a regular expression, as described in stringi::stringi-search-regex. Control options with regex(). Match a fixed string (i.e. by comparing only bytes), using fixed(). This is fast, but approximate. Generally, for matching human text, you'll want coll() which respects character matching rules for the specified locale. Match character, word, line and sentence boundaries with boundary(). An empty pattern, "", is equivalent to boundary("character").
n	number of pieces to return. Default (Inf) uses all possible split positions. For str_split_fixed, if n is greater than the number of pieces, the result will be padded with empty strings. For str_split_n, n is the desired index of each element of the split string. When there are fewer pieces than n, return NA.
simplify	If FALSE, the default, returns a list of character vectors. If TRUE returns a character matrix.

Value

For str_split_fixed, a character matrix with n columns. For str_split, a list of character vectors. For str_split_n, a length n character vector.

See also

stri_split() for the underlying implementation.

Examples

fruits <- c(
  "apples and oranges and pears and bananas",
  "pineapples and mangos and guavas"
)

str_split(fruits, " and ")
#> [[1]]
#> [1] "apples"  "oranges" "pears"   "bananas"
#> 
#> [[2]]
#> [1] "pineapples" "mangos"     "guavas"    
#> 
str_split(fruits, " and ", simplify = TRUE)
#>      [,1]         [,2]      [,3]     [,4]     
#> [1,] "apples"     "oranges" "pears"  "bananas"
#> [2,] "pineapples" "mangos"  "guavas" ""       

# Specify n to restrict the number of possible matches
str_split(fruits, " and ", n = 3)
#> [[1]]
#> [1] "apples"            "oranges"           "pears and bananas"
#> 
#> [[2]]
#> [1] "pineapples" "mangos"     "guavas"    
#> 
str_split(fruits, " and ", n = 2)
#> [[1]]
#> [1] "apples"                        "oranges and pears and bananas"
#> 
#> [[2]]
#> [1] "pineapples"        "mangos and guavas"
#> 
# If n greater than number of pieces, no padding occurs
str_split(fruits, " and ", n = 5)
#> [[1]]
#> [1] "apples"  "oranges" "pears"   "bananas"
#> 
#> [[2]]
#> [1] "pineapples" "mangos"     "guavas"    
#> 

# Use fixed to return a character matrix
str_split_fixed(fruits, " and ", 3)
#>      [,1]         [,2]      [,3]               
#> [1,] "apples"     "oranges" "pears and bananas"
#> [2,] "pineapples" "mangos"  "guavas"           
str_split_fixed(fruits, " and ", 4)
#>      [,1]         [,2]      [,3]     [,4]     
#> [1,] "apples"     "oranges" "pears"  "bananas"
#> [2,] "pineapples" "mangos"  "guavas" ""       

# str_split_n extracts only a single piece from a string
str_split_n(fruits, " and ", 1)
#> [1] "apples"     "pineapples"
str_split_n(fruits, " and ", 3)
#> [1] "pears"  "guavas"