在R中打开JSON文件

Question

I have downloaded some data from the following site as a zip file and extracted it onto my computer. Now, I'm having trouble trying to open the included json data files.

Running following code:

install.packages("rjson")
library("rjson")
comp <- fromJSON("statsbomb/data/competitions")

gave this error:

Error in fromJSON("statsbomb/data/competitions") : unexpected character 's'

Also, is there a way to load all files at once instead of writing individual statements each time?

Answer 1

Here is what I did(Unix system).

1. Clone the Github repo(mark location)

git clone https://github.com/statsbomb/open-data.git

2. Set working directory(directory to which you cloned the repo or extracted the zip file).

setwd("path to directory where you cloned the repo")

3. Read data.

  jsonlite::fromJSON("competitions.json")

With rjson : rjson::fromJSON(file="competitions.json")

4. To run all the files at once, move all .json files to a single directory and use lapply/assign to assign your objects to your environment.

Result(single file):

  competition_id season_id             country_name
1             37         4                  England
2             43         3            International
3             49         3 United States of America
4             72        30            International
         competition_name season_name              match_updated
1 FA Women's Super League   2018/2019    2019-06-05T22:43:14.514
2          FIFA World Cup        2018 2019-05-14T08:23:15.306297
3                    NWSL        2018 2019-05-17T00:35:34.979298
4       Women's World Cup        2019 2019-06-21T16:45:45.211614
             match_available
1    2019-06-05T22:43:14.514
2 2019-05-14T08:23:15.306297
3 2019-05-14T08:02:00.567719
4 2019-06-21T16:45:45.211614

Answer 2

The function fromJSON takes a JSON string as a first argument unless you specify you are giving a file ( fromJSON(file = "competitions.json") ).

The error you mention comes from the function trying to parse 'statsbomb/data/competitions' as a string and not a file name. In JSON however, everything is enclosed in brackets and strings are inside quotation marks. So the s from "statsbomb" is not a valid first character.

To read all json files you could do:

lapply(dir("open-data-master/",pattern="*.json",recursive = T), function(x) {
  assign(gsub("/","_",x), fromJSON(file = paste0("open-data-master/",x)), envir = .GlobalEnv)
})

however this will take a long time to complete! You probably should elaborate a little bit on this function. Eg split the list of files obtained with dir into chunks of 50 before running the lapply call.