stri_trim: Trim Characters from the Left and/or Right Side of a String

Description

These functions may be used, e.g., to remove unnecessary white-spaces from strings. Trimming ends at the first or starts at the last pattern match.

Usage

stri_trim_both(str, pattern = "\\P{Wspace}", negate = FALSE)

stri_trim_left(str, pattern = "\\P{Wspace}", negate = FALSE)

stri_trim_right(str, pattern = "\\P{Wspace}", negate = FALSE)

stri_trim(
  str,
  side = c("both", "left", "right"),
  pattern = "\\P{Wspace}",
  negate = FALSE
)

Arguments


`str`	a character vector of strings to be trimmed
`pattern`	a single pattern, specifying the class of characters (see stringi-search-charclass) to to be preserved (if `negate` is `FALSE`; default) or trimmed (otherwise)
`negate`	either `TRUE` or `FALSE`; see `pattern`
`side`	character [`stri_trim` only]; defaults to `'both'`

Details

Vectorized over str and pattern.

stri_trim is a convenience wrapper over stri_trim_left and stri_trim_right.

Contrary to many other string processing libraries, our trimming functions are universal. The class of characters to be retained or trimmed can be adjusted.

For replacing pattern matches with an arbitrary replacement string, see stri_replace.

Trimming can also be used where you would normally rely on regular expressions. For instance, you may get '23.5' out of 'total of 23.5 bitcoins'.

For trimming white-spaces, please note the difference between Unicode binary property ‘\p{Wspace}’ (more universal) and general character category ‘\p{Z}’, see stringi-search-charclass.

Value

All functions return a character vector.

Author(s)

Marek Gagolewski and other contributors

Examples

stri_trim_left('               aaa')
## [1] "aaa"
stri_trim_right('r-project.org/', '\\P{P}')
## [1] "r-project.org"
stri_trim_both(' Total of 23.5 bitcoins. ', '\\p{N}')
## [1] "23.5"
stri_trim_both(' Total of 23.5 bitcoins. ', '\\P{N}', negate=TRUE)
## [1] "23.5"