JSON to DF problem

[LucasMerolla]

I m working with a Rstudio code, i have 450 JSON files, i have all in my workspace, with some JSON files are all rigth, but with some files like this one (2.json - Google Drive , is a 296kb json) when i try to make the field tm to dataframe i have this mistake

Error in (function (..., row.names = NULL, check.rows = FALSE, check.names = TRUE, : arguments imply differing number of rows: 0, 1

The code that i use is

data = rjson::fromJSON(file = "2.json", simplify = T)
a = as.data.frame(data$tm)

With the files that are ok i obtain a 1 observation of x variables.

How can i avoid this priblem with some files?

Another posibility that i think is select the rows that i need

    candidatos = list(
"name",
"score",
"tot_sFieldGoalsMade",
"tot_sFieldGoalsAttempted",
"tot_sTwoPointersMade",
"tot_sTwoPointersAttempted",
"tot_sThreePointersMade",
"tot_sThreePointersAttempted",
"tot_sFreeThrowsMade",
"tot_sFreeThrowsAttempted",
"tot_sReboundsDefensive",
"tot_sReboundsOffensive",
"tot_sReboundsTotal",
"tot_sAssists",
"tot_sBlocks",
"tot_sTurnovers",
"tot_sFoulsPersonal",
"tot_sPointsInThePaint",
"tot_sPointsSecondChance",
"tot_sPointsFromTurnovers",
"tot_sBenchPoints",
"tot_sPointsFastBreak",
"tot_sSteals"
)

 ListColum<-map(candidatos, function(x){
    as.data.frame(data$tm$"2"$x)
     } )

But R give me a list of 23 DF with no elements

Thanks

[AlexisW]

For your file, I think the problem comes from data$tm$2$lds$sBlocks which is empty so can't be bound to the rest.

One way that can circumvent the problem is to use rbind:

a <- do.call(rbind, data)

It gives a warning but not an error. But I'm not sure if the format is the same as what you want.

---

@LucasMerolla

Another posibility that i think is select the rows that i need

The structure of the json file is quite complex, so if you're only interested in a few values that does seem like a good solution.

data$tm$"2"$x

This won't work: $ is only valid with a name, not with a variable containing the name. You need to use [[:

ListColum<-map(candidatos, function(x){
  as.data.frame(data$tm$"2"[[x]])
} )

The format is a big ugly though, map returns a list, and you put a data frame in each element. Also the names are meaningless. This will be better:

selected_values <- map_dfc(candidatos,
                           ~ data$tm$"2"[[.x]])
selected_values
names(selected_values) <- candidatos

Note that I changed the definition of candidatos to be a character vector rather than a list:

candidatos = c(
  "name",
  "score",
  "tot_sFieldGoalsMade",
   ...
)

Lists are a strange class and should only be used when the others are not possible.