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How to convert a csv to json with first column as key, and second and third one as values using jsonlite or other package?

byMR

December 1, 2022

Now I obtained:

[
  {
    "full": "f1",
    "semiabrv": "s1",
    "abrv": "a1"
  },
  {
    "full": "f2",
    "semiabrv": "s2",
    "abrv": "a2"
  }
]

What I expect to be used:

{

"f1": ["s1","a1"],

 "f2": ["s2","a2"]  
}

MWE:

fb <- structure(list(full = c("f1", "f2"), semiabrv = c("s1", "s2"), 
abrv = c("a1", "a2")), row.names = 1:2, class = "data.frame")

fb|> 
  jsonlite::toJSON(pretty=TRUE)

Thanks for any idea!

If any other package available, it also ok.

>Solution :

I was about to suggest dataframe="column", but your output assumes a bespoke use of using a value (in one column) as a name (for all other columns combined). For that, we need custom code (but not much).

jsonlite::toJSON(
  do.call(Map,
    c(list(f = function(nm, ...) c(...), fb$full), fb[-1])
  ), pretty = TRUE)
# {
#   "f1": ["s1", "a1"],
#   "f2": ["s2", "a2"]
# }

While it looks like we provide fb$full as nm= (in the anonfunc) and then discard it, I’m capitalizing on Map‘s tendency to use the first argument to define the names of the output.