从 R 中不常见的 JSON 结构中提取所有信息

Question

在之前的帖子 (How do I read multiple JSON structures contained in one file?) 中，我询问了一个不常见的数据结构（或者至少对于 R 来说不常见）

我有一个这样结构的txt文件：

identifier ### part A ### part B

我的真实数据的第一行的简化是这样的

1 ### [{"X": "1", "Y": "2", "Z": "3"}, {"X": "4", "Y": "5", "Z": "6"}] ### [{"X": "7", "Y": "8", "Z": "9"}, {"X": "10", "Y": "11", "Z": "12"}, {"X": "13", "Y": "14", "Z": "15"}]

此结构来自公共数据。

我用过这个

setwd("/myfolder")

library(stringi)
library(purrr)
library(jsonlite)

raw <- readLines("myfile.txt")

raw <- gsub("^.\\###", " ", raw)

PartB <- gsub("^.*\\]\\###\\[", "", raw)
PartB <- paste0("[", PartB)

PartB <- stri_replace_first_regex(PartB, "\\###", "") %>% 
  map_df(fromJSON)

save(fundamento, file = "PartB.RData")

PartA <- gsub(pattern = "(.*\\###)(.*)(\\###.*)", "\\2", raw)

PartA <- stri_replace_first_regex(concepto, "\\###", "") %>% 
  map_df(fromJSON)

save(PartA, file = "PartA.RData")

这会创建两个数据框

PartA

X Y Z
1 2 3
4 5 6

PartB

X  Y  Z
7  8  9
10 11 12
13 14 15

我试图获得这样的东西

PartA

identifier part X Y Z
1          A    1 2 3
1          A    4 5 6

PartB

identifier part X  Y  Z
1          B    7  8  9
1          B    10 11 12
1          B    13 14 15

任何想法都会有所帮助。非常感谢。

Answer 1

试试这个：

library(stringr)
library(tidyjson)
library(purrr)
library(dplyr)

line1 <- '### [{"X": "1", "Y": "2", "Z": "3"}, {"X": "4", "Y": "5", "Z": "6"}] ### [{"X": "7", "Y": "8", "Z": "9"}, {"X": "10", "Y": "11", "Z": "12"}, {"X": "13", "Y": "14", "Z": "15"}]'
line2 <- '### [{"X": "2", "Y": "3", "Z": "4"}, {"X": "5", "Y": "6", "Z": "7"}] ### [{"X": "8", "Y": "9", "Z": "10"}, {"X": "11", "Y": "12", "Z": "13"}, {"X": "14", "Y": "15", "Z": "16"}]'

raw <- c(line1, line2)

cleanup_line <- function(line, id) {

  line %>% gsub('^### ', '', .) %>% str_split('###') %>%
    flatten_chr %>%
    gather_array %>%
    spread_all %>%
    mutate(identifier = id, part = letters[document.id]) %>%
    select(identifier, part, X, Y, Z) %>%
    tbl_df

}

map2_df(raw, seq_along(raw), cleanup_line)

您需要 tidyjson 的开发版本才能使用 spread_all，否则您可以使用 CRAN 版本中更详细的 spread_values。