Revamping string elements

rstudio

#1

I have the following problem. I have a column with 7 characters (1234567), and I want to always remove the last character (7) leave it with only 6 characters (123456). But also preserve all columns of the dataframe.

How can I resolve this?

Thanks in advance!


#2

Could you ask this with a minimal REPRoducible EXample (reprex)? A reprex makes it much easier for others to understand your issue and figure out how to help.


#3

To keep only the 6 first character on a character vector of 7 character length, you could do it these ways with stringr :package:

vec <- c("123456", "abcdefg")
# select the first 6 character
stringr::str_sub(vec, start = 1, end = 6)
#> [1] "123456" "abcdef"
# or end before the last character
stringr::str_sub(vec, end = -2)
#> [1] "12345"  "abcdef"
# trunc with no evecpsis
stringr::str_trunc(vec, 6, ellipsis = "")
#> [1] "123456" "abcdef"

Created on 2018-08-14 by the reprex package (v0.2.0.9000).

To only apply this transformation to one column in a data.frame (or a tibble), you can do it with mutate in dplyr

library(dplyr, warn.conflicts = FALSE)
# create a tibble with dummy col for the reprex
data_frame(vec  = c("123456", "abcdefg"), other_col = c(1, 2), other_col2 = c("A", "B")) %>%
  # apply a transformation only specified columns
  mutate(
    # apply the transformation of the vec column
    vec = stringr::str_sub(vec, start = 1, end = 6)
  )
#> # A tibble: 2 x 3
#>   vec    other_col other_col2
#>   <chr>      <dbl> <chr>     
#> 1 123456         1 A         
#> 2 abcdef         2 B

Created on 2018-08-14 by the reprex package (v0.2.0.9000).

Hope it helps


#4

Thank you, it worked.
Sorry for the misunderstanding.


#5

Great!

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