Question

我有一个嵌套的JSON文件，具有以下结构：

{"category1": {"town1": 8,"town2": 2},"category2": {"town1": 4,"town2": 3}}

我想在以下结构中将JSON导入到R中：

categories  towns   number
category1   town1   8
category1   town2   2
category2   town1   4
category2   town2   3

我尝试使用JSON，也使用Flatten = TRUE，但这并没有给我我想要的东西。我可以在R中做什么来获得我想要的结构？

Answer 1

json <- fromJSON('{"category1": {"town1": 8,"town2": 2},"category2":{"town1": 4,"town2": 3}}') 

json <- data.frame(number = unlist(json))

json$rownames <- rownames(json) 

rownames(json) <- NULL

json$categories <- lapply(strsplit(as.character(json$rownames), "\\."), "[", 1)

json$town <- lapply(strsplit(as.character(json$rownames), "\\."), "[",2) 

json$rownames <- NULL

Answer 2

诀窍是使用stack：

library(jsonlite)
lst = fromJSON(json)
transform(stack(lst), towns=c(sapply(lst, names)))

#  values       ind towns
#1      8 category1 town1
#2      2 category1 town2
#3      4 category2 town1
#4      3 category2 town2

使用plyr，简洁的一行是：

library(plyr)
ldply(fromJSON(json), stack)

数据：

json = '{"category1": {"town1": 8,"town2": 2},"category2": {"town1": 4,"town2": 3}}'

嵌套JSON到R中的数据框架

2 个答案: