How to split a column in R based upon how many characters there are in each element?

I have a column in my data named Sex/neuter status. The values that may appear are male, male entire, male neutered. I would like to create another column to separate this into column 1: sex and column 2: neuter status. For each case I would like the sex to appear in column 1 and its neuter status to appear in column 2. There will be some neuter status' missing for some cases but each case will have sex recorded.

Example data:

Data = data.frame(CaseID = c('1','2','3','4','5'), sexneuterstatus =c('male','maleneutered','maleentire','male','maleneutered'))                  

I have tried to use the split function but have had no luck.

I assume i need to split the column based on the number of characters, i.e., if there are 2 this means neuter status is present so send the second value (neuter status) to a new column. However, i dont know how I would do this.

Please help!

You can use tidyr::separate with a regex look behind, this assumes that male always precedes the neuter status in the original data frame and that male is the only gender, i.e. no cases of female.

library(tidyr)

Data = data.frame(CaseID = c('1','2','3','4','5'), sexneuterstatus =c('male','maleneutered','maleentire','male','maleneutered'))

df_new <- 
  Data |> 
  separate(col = sexneuterstatus, into = c("sex", "status"), sep = "(?<=male)")

df_new

#>   CaseID  sex   status
#> 1      1 male         
#> 2      2 male neutered
#> 3      3 male   entire
#> 4      4 male         
#> 5      5 male neutered

^{Created on 2023-07-03 with reprex v2.0.2}