See the differences with these examples > grepl(“\\.”, “Hello.”) [1] TRUE > grepl(“\\.”, “Hello”) [1] FALSE the . means anything as pointed out by SimonO101, if you want to look for an explicit . then you have to skip it by using \\. which means look for a . R documentation is extensive on regular … Read more
“\<” is another escape sequence for the beginning of a word, and “\>” is the end. In R strings you need to double the backslashes, so: > grepl(“\\<is\\>”, c(“this”, “who is it?”, “is it?”, “it is!”, “iso”)) [1] FALSE TRUE TRUE TRUE FALSE Note that this matches “is!” but not “iso”.
You could paste the genres together with an “or” | separator and run that through grepl as a single regular expression. x <- c(“Action”, “Adventure”, “Animation”, …) grepl(paste(x, collapse = “|”), my_text) Here’s an example. x <- c(“Action”, “Adventure”, “Animation”) my_text <- c(“This one has Animation.”, “This has none.”, “Here is Adventure.”) grepl(paste(x, collapse = … Read more
Although stringr ICU regex engines supports bare POSIX character classes in the pattern, in base R regex flavors (both PCRE (perl=TRUE) and TRE), POSIX character classes must be inside bracket expressions. [:alnum:] -> [[:alnum:]]. x <- c(“AZaz09 y AZaz09”, “ĄŻaz09 y AZŁł09”, “26 de Marzo y Pareyra de la Luz”) grepl(“[[:alnum:][:blank:]]+[[:blank:]][yY][[:blank:]][[:alnum:][:blank:]]+”, x) ## => [1] … Read more