How do I read multiple JSON structures contained in one file?

问题

I have a .txt file with this structure

section1#[{"p": "0.999834", "tag": "MA"},{"p": "1", "tag": "MO"},...etc...}]
section1#[{"p": "0.9995", "tag": "NC"},{"p": "1", "tag": "FL"},...etc...}]
...
section2#[{"p": "0.9995", "tag": "NC"},{"p": "1", "tag": "FL"},...etc...}]

I am trying to read it by using R with the commands

library(jsonlite)
data <- fromJSON("myfile.txt")

But I get this

Error in feed_push_parser(readBin(con, raw(), n), reset = TRUE) : 
  lexical error: invalid char in json text.
                                       section2#[{"p": "0.99
                     (right here) ------^

How can I read it even by splitting by sections?

回答1:

Remove the prefix and bind the flattened JSON arrays together into a data frame:

raw_dat <- readLines(textConnection('section1#[{"p": "0.999834", "tag": "MA"},{"p": "1", "tag": "MO"}]
section1#[{"p": "0.9995", "tag": "NC"},{"p": "1", "tag": "FL"}]
section2#[{"p": "0.9995", "tag": "NC"},{"p": "1", "tag": "FL"}]'))

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

stri_replace_first_regex(raw_dat, "^section[[:digit:]]+#", "") %>% 
  map_df(fromJSON)
##          p tag
## 1 0.999834  MA
## 2        1  MO
## 3   0.9995  NC
## 4        1  FL
## 5   0.9995  NC
## 6        1  FL

回答2:

Remove section# from each line. Then your .txt will have a 2D array with JSON objects at each index. You can access elements by accessing it as foo[0][0] being the first object of first line and foo[m][n] where m is the number of sections -1 and n is number of objects in each section -1

来源：https://stackoverflow.com/questions/39400580/how-do-i-read-multiple-json-structures-contained-in-one-file

标签

json

jsonlite