Importing data from a JSON file into R [duplicate] - json

Question

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Parse JSON with R
(6 answers)
Closed 2 years ago.
Is there a way to import data from a JSON file into R? More specifically, the file is an array of JSON objects with string fields, objects, and arrays. The RJSON Package isn't very clear on how to deal with this http://cran.r-project.org/web/packages/rjson/rjson.pdf.

Answer 1

First install the rjson package:
install.packages("rjson")
Then:
library("rjson")
json_file <- "http://api.worldbank.org/country?per_page=10&region=OED&lendingtype=LNX&format=json"
json_data <- fromJSON(paste(readLines(json_file), collapse=""))
Update: since version 0.2.1
json_data <- fromJSON(file=json_file)

Answer 2

jsonlite will import the JSON into a data frame. It can optionally flatten nested objects. Nested arrays will be data frames.
> library(jsonlite)
> winners <- fromJSON("winners.json", flatten=TRUE)
> colnames(winners)
[1] "winner" "votes" "startPrice" "lastVote.timestamp" "lastVote.user.name" "lastVote.user.user_id"
> winners[,c("winner","startPrice","lastVote.user.name")]
winner startPrice lastVote.user.name
1 68694999 0 Lamur
> winners[,c("votes")]
[[1]]
ts user.name user.user_id
1 Thu Mar 25 03:13:01 UTC 2010 Lamur 68694999
2 Thu Mar 25 03:13:08 UTC 2010 Lamur 68694999

Answer 3

An alternative package is RJSONIO. To convert a nested list, lapply can help:
l <- fromJSON('[{"winner":"68694999", "votes":[
{"ts":"Thu Mar 25 03:13:01 UTC 2010", "user":{"name":"Lamur","user_id":"68694999"}},
{"ts":"Thu Mar 25 03:13:08 UTC 2010", "user":{"name":"Lamur","user_id":"68694999"}}],
"lastVote":{"timestamp":1269486788526,"user":
{"name":"Lamur","user_id":"68694999"}},"startPrice":0}]'
)
m <- lapply(
l[[1]]$votes,
function(x) c(x$user['name'], x$user['user_id'], x['ts'])
)
m <- do.call(rbind, m)
gives information on the votes in your example.

Answer 4

If the URL is https, like used for Amazon S3, then use getURL
json <- fromJSON(getURL('https://s3.amazonaws.com/bucket/my.json'))

Answer 5

First install the RJSONIO and RCurl package:
install.packages("RJSONIO")
install.packages("(RCurl")
Try below code using RJSONIO in console
library(RJSONIO)
library(RCurl)
json_file = getURL("https://raw.githubusercontent.com/isrini/SI_IS607/master/books.json")
json_file2 = RJSONIO::fromJSON(json_file)
head(json_file2)

Answer 6

load the packages:
library(httr)
library(jsonlite)
I have had issues converting json to dataframe/csv. For my case I did:
Token <- "245432532532"
source <- "http://......."
header_type <- "applcation/json"
full_token <- paste0("Bearer ", Token)
response <- GET(n_source, add_headers(Authorization = full_token, Accept = h_type), timeout(120), verbose())
text_json <- content(response, type = 'text', encoding = "UTF-8")
jfile <- fromJSON(text_json)
df <- as.data.frame(jfile)
then from df to csv.
In this format it should be easy to convert it to multiple .csvs if needed.
The important part is content function should have type = 'text'.

Answer 7

import httr package
library(httr)
Get the url
url <- "http://www.omdbapi.com/?apikey=72bc447a&t=Annie+Hall&y=&plot=short&r=json"
resp <- GET(url)
Print content of resp as text
content(resp, as = "text")
Print content of resp
content(resp)
Use content() to get the content of resp, but this time do not specify
a second argument. R figures out automatically that you're dealing
with a JSON, and converts the JSON to a named R list.