I have a list of dataframes for which I would like to turn one of their cols into the rownames.
(instead of doing this for every df individually).

Unfortunatly I cant get it to work, maybe someone can help?

```
DF1 <- data.frame(A = c("A", "B", "C"),
                  B = 1:3)
DF2 <- data.frame(A = c("A", "B", "C"),
                  B = 1:3)
TheList <- list(DF1 = DF1,
                DF2 = DF2)
col_to_rownames_andDel <- function(df){
  rownames(df) <- df$A
  df$A <- NULL
}

TheList_namedRows <- map(TheList, col_to_rownames_andDel) #not working and empties the dfs

```

Thanks!

Sebastian