On Wed, 3 Apr 2019 15:01:37 +0100 Graham Leask via R-help <r-help@r-project.org> wrote:
Suppose that `BHC$Date` contains a string "M_24". You do: > BHC <-BHC %>% mutate ( Date = stringr :: str_replace ( Date , "M_2" , > "01-04-2017")) before you have a chance to do: > BHC <-BHC %>% mutate ( Date = stringr :: str_replace ( Date , > "M_24" , "01-02-2019")) So now it has "01-04-20174" because the first expression had a successful match and already made a replacement. help() for stringi::stringi-search-regex says that look-around expressions are supported, so one of the ways to prevent this would be to modify your patterns to look like e.g. 'M_2(?!\\d)' to match 'M_2' that is *not* followed by a digit. -- Best regards, Ivan ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
