How to extract initial, last, or middle characters from a string in R?
https://www.tutorialspoint.com/how-to-extract-initial-last-or-middle-characters-from-a-string-in-r
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12-09-2020 - |
Question
How to extract initial, last, or middle characters from a string in R?
In Text analysis, we might want to extract characters from a single string or from a vector of strings. This extraction might be required to create a new string with some specific words required for further analysis. We can do this with the help of str_sub function of stringr package.
Example
Consider the below string −
> x1<-"Removing harmful things from the road is an act of charity"
Loading the stringr package −
> library(stringr) > str_sub(x1,1,8) [1] "Removing" > str_sub(x1,1,23) [1] "Removing harmful things" > str_sub(x1,29,37) [1] " the road" > str_sub(x1,30,37) [1] "the road" > str_sub(x1,-58,-51) [1] "Removing" > str_sub(x1,-58,-1) [1] "Removing harmful things from the road is an act of charity" > str_sub(x1,-7,-1) [1] "charity" > str_sub(x1,-14,-1) [1] "act of charity" > str_sub(x1,-17,-1) [1] "an act of charity"
Let’s have a look at extraction of number of characters for a vector of strings −
> x1<-c("Removing", "harmful", "things", "from", "the", "road", "is", "an", "act", "of", "charity") > str_sub(x1,1,2) [1] "Re" "ha" "th" "fr" "th" "ro" "is" "an" "ac" "of" "ch" > str_sub(x1,1,3) [1] "Rem" "har" "thi" "fro" "the" "roa" "is" "an" "act" "of" "cha" > str_sub(x1,1,10) [1] "Removing" "harmful" "things" "from" "the" "road" [7] "is" "an" "act" "of" "charity" > str_sub(x1,-7,-2) [1] "emovin" "harmfu" "thing" "fro" "th" "roa" "i" "a" [9] "ac" "o" "charit" > str_sub(x1,-7,-1) [1] "emoving" "harmful" "things" "from" "the" "road" "is" [8] "an" "act" "of" "charity" > str_sub(x1,-10,-1) [1] "Removing" "harmful" "things" "from" "the" "road" [7] "is" "an" "act" "of" "charity"
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