str_extract_before: Extract characters in a string which occur before a specified...

In johncassil/stringr.plus: string functions that are "too specific for stringr" for Hadley Wickham

Description

Vectorised over 'string' and 'pattern'.

Usage

str_extract_before(string, pattern, which = "first", num_char = NULL)

Arguments

string	The string from which to extract.
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").
which	If there are multiple patterns, should the function bring back the "first" or "last" occurrence?
num_char	The number of characters to return from before the pattern. Leave NULL to return everything before the pattern.

Value

The part of the string before the pattern.

Examples

test_string <- 'url.com/string_before_pattern_after-another_string_with_pattern2/'
str_extract_before(string = test_string, pattern = '_pattern_')
str_extract_before(string = test_string, pattern = '_pattern_', num_char = 6)
str_extract_before(string = test_string, pattern = '_', which = "last")

johncassil/stringr.plus documentation built on Oct. 9, 2021, 7:56 p.m.