user1477388 user1477388 - 4 months ago 10
R Question

Unimplemented type list when trying to write.table

I have the following data.table (data.frame) called output:

> head(output)
Id Title IsProhibited
1 10000074 Renault Logan, 2005 0
2 10000124 Ñêëàäñêîå ïîìåùåíèå, 345 ì<U+00B2> 0
3 10000175 Ñó-øåô 0
4 10000196 3-ê êâàðòèðà, 64 ì<U+00B2>, 3/5 ýò. 0
5 10000387 Samsung galaxy S4 mini GT-I9190 (÷¸ðíûé) 0
6 10000395 Êàðòèíà ""Êðûì. Ïîñåëîê Àðîìàò"" (õîëñò, ìàñëî) 0


I am trying to export it to a CSV like so:

> write.table(output, 'output.csv', sep = ',', row.names = FALSE, append = T)


However, when doing so I get the following error:

Error in .External2(C_writetable, x, file, nrow(x), p, rnames, sep, eol, :
unimplemented type 'list' in 'EncodeElement'
In addition: Warning message:
In write.table(output, "output.csv", sep = ",", row.names = FALSE, :
appending column names to file


I have tried converting the
Title
to a string so that it is no longer of type
list
like so:

toString(output$Title)


But, I get the same error. My types are:

> class(output)
[1] "data.frame"
> class(output$Id)
[1] "integer"
> class(output$Title)
[1] "list"
> class(output$IsProhibited)
[1] "factor"


Can anyone tell me how I can export my data.frame to CSV?

Another strange thing that I've noticed, is that if I write
head(output)
my text is not encoded properly (as shown above) whereas if I simply write
output$Title[0:3]
it will display the text correctly like so:

> output$Title[0:3]
[[1]]
[1] "Renault Logan, 2005"

[[2]]
[1] "Складское помещение, 345 м²"

[[3]]
[1] "Су-шеф"


Any ideas regarding that? Is it relevant to my initial problem?

Edit: Here is my new output:

Id Title IsProhibited
10000074 Renault Logan, 2005 0
10000124 СкладÑкое помещение, 345 м<U+00B2> 0
10000175 Су-шеф 0
10000196 3-к квартира, 64 м<U+00B2>, 3/5 ÑÑ‚. 0
10000387 Samsung galaxy S4 mini GT-I9190 (чёрный) 0
10000395 Картина \\"Крым. ПоÑелок Ðромат\"\" (холÑÑ‚ маÑло)" 0
10000594 КальÑн 25 Ñм 0
10000612 1-к квартира, 45 м<U+00B2>, 6/17 ÑÑ‚. 0
10000816 Гараж, 18 м<U+00B2> 0
10000831 Платье 0
10000930 Карбюраторы К-22И, К-22Г от газ 21 и газ 51 0


Notice how line ID 10000395 is messed up? It seems to contains quotes of it's own which are messing up the CSV. How can I fix that?

Answer

As mentioned in the comments, you should be able to do something like this (untested) to get "flatten" your list into a character vector:

output$Title <- vapply(output$Title, paste, collapse = ", ", character(1L))

As also mentioned, if you wanted to try the unlist approach, you could "expand" each row by the individual values in output$Title, something like this:

x <- vapply(output$Title, length, 1L)          ## How many items per list element
output <- output[rep(rownames(output), x), ]   ## Expand the data frame
output$Title <- unlist(output$Title, use.names = FALSE)  ## Replace with raw values