How Can I grepl a word including a letter?

General
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#1

My question is clear I guess. I want to get certain words which are including X,J,Q or W. How can I do that? I find some solutions but they explain if word starts with one of these letters. I want all values including this letter move to another datatable how can I do this? I've tried

grepl("^X.*?") and it didnt work for words that start with X. any suggestions? Thank you.

#2

If you want to check if an entry in your character vector contains any of those letters anywhere within the string, you can use the regex pattern "[XJWQ]", which will search for any of the values inside the square brackets anywhere within the characters:

set.seed(040915)
testers <- stringi::stri_rand_strings(100,5)
found_it <- grepl("[XJQW]",testers)
testers[found_it]
#3

Here is an example what I want to achieve.

DT1 <- data.table(ZipCodes = c("20202","10101","00023","40404","00001","25002"),
                  Cities =c("Xi'an/China","Washington D.C","Johannesburg","NewYork/US","Quebeck","Houston"))
#> ZipCodes      Cities
#> 20202           Xi'an/China
#> 10101           Washington D.C
#> 00023           Johennesburg
#> 40404           NewYork/US
#> 00001           Quebec
#> 25002           Houston

What I want is when I use grepl search entries that has "X W J and Q" in DT1$Cities and grab entire row to DT2. I couldnt manage it with grepl("[XWJQ]",DT1$cities) or grepl("^X.*?",DT1$Cities)

In the end DT2 should be seen like this.

DT2 <- data.table(ZipCodes = c("20202","10101","00023","40404","00001"),
                  Cities =c("Xi'an/China","Washington D.C","Johannesburg","NewYork/US","Quebeck"))

#> ZipCodes      Cities
#> 20202           Xi'an/China
#> 10101           Washington D.C
#> 00023           Johennesburg
#> 40404           NewYork/US
#> 00001           Quebec
#4

In the piece of code you included, the cities variable is in lower case, and based on your target DT2, you want lowercase letters to be matched. Try this:

DT1 <- data.table(ZipCodes = c("20202","10101","00023","40404","00001","25002"),
                  Cities =c("Xi'an/China","Washington D.C","Johannesburg","NewYork/US","Quebeck","Houston"))

DT2 <- DT1[grepl("[XJWQxwjq]",DT1$Cities),]
1 Like
#5

Thank you totally my bad I miss placed the '|' operator last night was super tired.

#6

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