如何在 R 中解析具有堆叠多个 JSON 的文件？

Question

我在 R 中有以下 "stacked JSON" 对象，example1.json:

{"ID":"12345","Timestamp":"20140101", "Usefulness":"Yes",
  "Code":[{"event1":"A","result":"1"},…]}
{"ID":"1A35B","Timestamp":"20140102", "Usefulness":"No",
  "Code":[{"event1":"B","result":"1"},…]}
{"ID":"AA356","Timestamp":"20140103", "Usefulness":"No",
  "Code":[{"event1":"B","result":"0"},…]}

这些不是逗号分隔的。基本目标是将某些字段（或所有字段）解析为 R data.frame 或 data.table:

    Timestamp    Usefulness
 0   20140101      Yes
 1   20140102      No
 2   20140103      No

通常，我会在 JSON 中读取 R 中的内容，如下所示：

library(jsonlite)

jsonfile = "example1.json"
foobar = fromJSON(jsonfile)

然而，这会引发解析错误：

Error: lexical error: invalid char in json text.
          [{"event1":"A","result":"1"},…]} {"ID":"1A35B","Timestamp"
                     (right here) ------^

这是一个与以下类似的问题，但在 R 中：

编辑：此文件格式称为 "newline delimited JSON"、NDJSON。

Answer 1

三个点 ... 使您的 JSON 无效，因此您的 lexical error.
您可以使用 jsonlite::stream_in() 到 'stream in' 行 JSON。

library(jsonlite)

jsonlite::stream_in(file("~/Desktop/examples1.json"))
# opening file input connection.
# Imported 3 records. Simplifying...
# closing file input connection.
#      ID Timestamp Usefulness Code
# 1 12345  20140101        Yes A, 1
# 2 1A35B  20140102         No B, 1
# 3 AA356  20140103         No B, 0

数据

我已经清理了您的示例数据以使其有效 JSON 并将其作为 ~/Desktop/examples1.json

保存到我的桌面

{"ID":"12345","Timestamp":"20140101", "Usefulness":"Yes","Code":[{"event1":"A","result":"1"}]}
{"ID":"1A35B","Timestamp":"20140102", "Usefulness":"No","Code":[{"event1":"B","result":"1"}]}
{"ID":"AA356","Timestamp":"20140103", "Usefulness":"No","Code":[{"event1":"B","result":"0"}]}

如何在 R 中解析具有堆叠多个 JSON 的文件？

How to parse a file with stacked multiple JSONs in R?

r

json

jsonlite

数据