Split delimited strings in a column and insert as new rows

data-manipulation, dataframe, r, reshape, strsplit

Solution

Here is another way of doing it..

df <- read.table(textConnection("1|a,b,c\n2|a,c\n3|b,d\n4|e,f"), header = F, sep = "|", stringsAsFactors = F)

df
##   V1    V2
## 1  1 a,b,c
## 2  2   a,c
## 3  3   b,d
## 4  4   e,f

s <- strsplit(df$V2, split = ",")
data.frame(V1 = rep(df$V1, sapply(s, length)), V2 = unlist(s))
##   V1 V2
## 1  1  a
## 2  1  b
## 3  1  c
## 4  2  a
## 5  2  c
## 6  3  b
## 7  3  d
## 8  4  e
## 9  4  f

Problem

I have a data frame as follow: ``` +-----+-------+ | V1 | V2 | +-----+-------+ | 1 | a,b,c | | 2 | a,c | | 3 | b,d | | 4 | e,f | | . | . | +-----+-------+ ``` Each of the alphabet is a character separated by comma. I would like to split V2 on each comma and insert the split strings as new rows. For instance, the desired output will be: ``` +----+----+ | V1 | V2 | +----+----+ | 1 | a | | 1 | b | | 1 | c | | 2 | a | | 2 | c | | 3 | b | | 3 | d | | 4 | e | | 4 | f | +----+----+ ``` I am trying to use `strsplit()` to spit V2 first, then cast the list into a data frame. It didn't work. Any help will be appreciated.

Original source

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