Split columns in dataframe with NA

Question

I have a df like this:

df <- data.frame(FOO = c(\'A|B|C\', \'A|B\', \'B|C\', \'A\', \'C\'))

> df
    FOO
1 A|B|C
2   A|B
3   B|C
4     A
5            


        

Answer 1

In base R:

df <- data.frame(FOO = c('A|B|C', 'A|B', 'B|C', 'A', 'C'))

dummy <- strsplit(as.character(df$FOO), "[|]")
want <- data.frame(values = unlist(dummy),
                   ids = rep(1:length(dummy), unlist(lapply(dummy, length))), 
                   stringsAsFactors = FALSE)

library(reshape2)
want <- dcast(want, ids ~ values, value.var = "values", fill = " ")[, -1] # first col removed
names(want) <- paste0("X", seq_along(unique(unlist(dummy)))) 
want
# X1 X2 X3
#1  A  B  C
#2  A  B   
#3     B  C
#4  A      
#5        C