R semicolon delimited a column into rows

Question

I am using RStudio 2.15.0 and have created an object from Excel using XLConnect with 3000+ rows and 12 columns I am trying to delimit/split a column into the rows but don\'t

Answer 1

You could try unnest from tidyr after splitting the "PolId" column and get the unique rows

library(dplyr)
library(tidyr)
 unnest(setNames(strsplit(df$PolId, ';'), df$Description), 
                                  Description) %>% unique()

Or using base R with stack/strsplit/duplicated. Split the "PolId" (strsplit) by the delimiter(;), name the output list elements with "Description" column, stack the list to get a 'data.frame' and use duplicated to remove the duplicate rows.

df1 <- stack(setNames(strsplit(df$PolId, ';'), df$Description))
setNames(df1[!duplicated(df1),], names(df))
#     PolId Description
#1  ABC123       TEST1
#2  ABC456       TEST1
#3  ABC789       TEST1
#10 AAA123       TEST1
#11 AAA123       TEST2
#12 ABB123       TEST3
#13 ABC123       TEST3

Or another option without using strsplit

v1 <- with(df, tapply(PolId, Description, FUN= function(x) {
            x1 <- paste(x, collapse=";")
        gsub('(\\b\\S+\\b)(?=.*\\b\\1\\b.*);', '', x1, perl=TRUE)}))
library(stringr)
Description <- rep(names(v1),  str_count(v1, '\\w+'))
PolId <- scan(text=gsub(';+', ' ', v1), what='', quiet=TRUE)
data.frame(PolId, Description)
#   PolId Description
#1 ABC123       TEST1
#2 ABC456       TEST1
#3 ABC789       TEST1
#4 AAA123       TEST1
#5 AAA123       TEST2
#6 ABB123       TEST3
#7 ABC123       TEST3