Simple when you know how! Thanks
Sent from mobile device - please excuse any spelling mistakes. ------ Original Message ------ From: William Dunlap To: Bernard McGarvey Cc: Ivan Krylov, r-help@r-project.org Sent: February 11, 2019 at 4:29 PM Subject: Re: [R] Difficulty with "\\" in string functions.... You can also avoid the issue by using the basename and dirname functions. >Fname1<- "D:\\Data\\OneDrive\\ISTA Documents\\QT_App\\QT Analysis Input Data >Example WorkBook.xlsx" >basename(Fname1) [1] "QT Analysis Input Data Example WorkBook.xlsx" >dirname(Fname1) [1] "D:/Data/OneDrive/ISTA Documents/QT_App" Use normalizePath if you need to convert those / to \ on Windows. Bill Dunlap TIBCO Software wdunlaptibco.com(http://tibco.com) On Mon, Feb 11, 2019 at 12:26 PM Bernard McGarvey<mcgarvey.bern...@comcast.net(mailto:mcgarvey.bern...@comcast.net)>wrote: > Brilliant! Thanks a million Ivan. > > Lion Bernard McGarvey > > > Director, Fort Myers Beach Lions Foundation, Inc. > > > Retired (Lilly Engineering Fellow). > > > >On February 11, 2019 at 3:13 PM Ivan > >Krylov<krylov.r...@gmail.com(mailto:krylov.r...@gmail.com)>wrote: > > > > > >On Mon, 11 Feb 2019 15:01:16 -0500 (EST) > >Bernard > >McGarvey<mcgarvey.bern...@comcast.net(mailto:mcgarvey.bern...@comcast.net)>wrote: > > > >>Now I try to split it using > >> > >> > >>str_split(Fname1,"\\") > >> > >> > >>but this returns an error > >> > >> > >>Error in stri_split_regex(string, pattern, n = n, simplify = > >>simplify, : Unrecognized backslash escape sequence in pattern. > >>(U_REGEX_BAD_ESCAPE_SEQUENCE) > > > >This happens because the second parameter of str_split is by default a > >regular expression, and a backslash has a special meaning in regular > >expressions: when preceding other characters, it may change the way > >they are interpreted. (For example, w means a literal "w" > >character, while \w means "any alphanumeric character". On the > >other hand, [ starts a character group, but \[ means just an opening > >square bracket.) See ?regex for more info on that. > > > >Since you want a literal backslash, you need to escape it with another > >backslash: \\ > > > >But to write a string literal of a double-backslash in R, you need to > >escape both backslash characters, each with their own backslash: "\\\\" > > > >## fname<- "D:\\Data\\OneDrive\\ISTA Documents\\QT_App\\QT Analysis > >Input Data Example WorkBook.xlsx" > >## message("\\\\") > >\\ > >## str_split(fname, "\\\\") > >[[1]] > >[1] "D:" > >[2] "Data" > >[3] "OneDrive" > >[4] "ISTA Documents" > >[5] "QT_App" > >[6] "QT AnalysisInput Data Example WorkBook.xlsx" > > > >You can also avoid all layers of the backslash hell (except the first) > >if you choose to split by fixed strings instead of regular expressions > >by using stringr::fixed: > > > >## str_split(fname, fixed("\\")) > > > >-- > >Best regards, > >Ivan > > ______________________________________________ > R-help@r-project.org(mailto: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 guidehttp://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. [[alternative HTML version deleted]] ______________________________________________ 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.
