Text mining with R (stringr)

Question

I have a string lenght 15 and want to remove the first 70 charac. and the last 200 charac. each.

I tried the following code to remove the beginnings and it didn’t work:

 texto2009a <- texto2009 %>% map(str_sub(., 1, 72) <- " ")

Answer 1

Fictional example, which may be reproduced for your case:

x<-c('Bem-vinda ao Stack Overflow em Português')

library(stringr)

str_sub(x, 2, -10) # as aspas do texto também contam como strings. Por isso, adicione uma unidade a mais
#[1] "em-vinda ao Stack Overflow em "

Where, 2 and -10 are respectively the amounts of initial and final characters that you want to remove.

Answer 2

From the @Giovani response, I wrote a small function to solve the difference problem between what str_sub does and what the question asks.

On the page help("str_sub"), section Details:

Details

Substrings are inclusive - they include the characters at Both start and end positions. str_sub(string, 1, -1) will Return the complete substring, from the first Character to the last.

Now the question asks (edited by me)

remove the first m characters and the latter n characters

It is therefore necessary to start at m + 1 and in the end it will be n - 1.

library(stringr)

str_sub_als <- function(s, primeiros = 70, ultimos = -200){
    str_sub(s, primeiros + 1, ultimos - 1)
}

x <- c("1234567890", "abcdefghijklmnopqrstuvwxyz")

str_sub(x, 3, -4)
#[1] "34567"                 "cdefghijklmnopqrstuvw"

str_sub_als(x, 3, -4)
#[1] "456"                 "defghijklmnopqrstuv"