How to replicate a function for a nested list

Question

I have a nested list (datalist) which I'd like to repeat the following function for. Within datalist are multiple dataframes (e.g., A-F).

After doing the following for the nested dataframe "A", I'd like to run it for the other nested dataframes (B-F):

dat_A_dat<-datalist["A"]
dat_A <- dat_A_dat$"A"[,c(1:4,7)] #note: I have to use $ to access this
dat_A.v <-dat_A[,c(1,2)]
dat_A.b <-dat_A[,3]
dat_A.c <-dat_A[,4]
dat_A.r <-dat_A[,7]

Is there a simpler way of doing this?

Your help would be greatly appreciated. Thank you all.

Answer 1

Its not clear what structure your data is or what exactly you're trying to achieve, but if you're just asking how to write a function that can be applied to each element of the list then it would be something like as follows.

Note: you might have to change this depending on the structure of your data and what you are trying to achieve, in future try to include a reproducible example

my_extraction_function <- function(d_list) {

    dat <- d_list$"A"[,c(1:4,7)] #note: I have to use $ to access this
    dat.v <-dat[,c(1,2)]
    dat.b <-dat[,3]
    dat.c <-dat[,4]
    dat.r <-dat[,7]

    # Return them in whatever format you want
    list(v = dat.v,
         b = dat.b,
         c = dat.c,
         r = dat.r)
}

You can then do:

my_extraction_function(datalist[["A"]])
my_extraction_function(datalist[["B"]])
... etc.

or

lapply(datalist, my_extraction_function)