r - How to write a data-frame with one column a list to a file?

Question

Here is my dummy dataset:

dataset<-data.frame(a=c(1,2,3,4),b=c('a','b','c','d'), c=c("HI","DD","gg","ff"))
g=list(c("a","b"),c(2,3,4), c(44,33,11,22),c("chr","ID","i","II"))
dataset$l<-g
dataset

 a b  c              l
1 1 a HI           a, b
2 2 b DD        2, 3, 4
3 3 c gg 44, 33, 11, 22
4 4 d ff chr, ID, i, II

> mode(dataset$l)
[1] "list"

when I try to write the dataset to a file:

> write.table(dataset, "dataset.txt", quote=F, sep="")
Error in write.table(x, file, nrow(x), p, rnames, sep, eol, na, dec, as.integer(quote),  : 
  unimplemented type 'list' in 'EncodeElement'

How can i solve this problem?

Answer 1

Output from save is unreadable. Output from dump or dput is ASCII and is readable to people who understand the structure of R objects, but I'm guessing you wanted it more conventionally arranged.

>  apply(dataset, 1, function(x) paste(x, sep=",", collapse=","))
[1] "1,a,HI,c("a", "b")"                  
[2] "2,b,DD,c(2, 3, 4)"                       
[3] "3,c,gg,c(44, 33, 11, 22)"                
[4] "4,d,ff,c("chr", "ID", "i", "II")"

The backslashes do not appear in the text-file output:

 writeLines(con="test.txt", apply(dataset, 1, function(x) paste(x, sep=",", collapse=",")))
#-------output-----
1,a,HI,c("a", "b")
2,b,DD,c(2, 3, 4)
3,c,gg,c(44, 33, 11, 22)
4,d,ff,c("chr", "ID", "i", "II")