Flatten JSON list into data frame

Question

I have a directory of 143 JSON files (~30 MB), which I would like to combine and convert to a flat data frame. (This might be related to this question, but I couldn't get that solution to work. See bottom for results.)

I'm able to parse a single element just fine, so I think my stumbling block is captured by the reprex below:

chr <- "[{\"sometext_lets_pretend_its_JSON\":999}]"
my_list <- list(chr, chr, chr, chr, chr, chr)
library(purrr)
my_list %>% 
    map(~ fromJSON(.x))

#[[1]]
#  sometext_lets_pretend_its_JSON
#1                            999
#
#[[2]]
#  sometext_lets_pretend_its_JSON
#1                            999
#
#[[3]]
#  sometext_lets_pretend_its_JSON
#1                            999
#
#[[4]]
#  sometext_lets_pretend_its_JSON
#1                            999
#
#[[5]]
#  sometext_lets_pretend_its_JSON
#1                            999
#
#[[6]]
#  sometext_lets_pretend_its_JSON
#1                            999

I'm trying to get a data frame that shows all the rows from the source files, but the flattened version only shows the first element. What am I doing wrong here?

my_list %>% 
    map(~ fromJSON(.x)) %>%
    flatten_dfr()
## A tibble: 1 x 1
#  sometext_lets_pretend_its_JSON
#                           <int>
#1                            999

score 2 · Accepted Answer · answered Dec 11 '18 at 02:03

Do you mean this?

my_list %>%
    map(~ fromJSON(.x)) %>%
    bind_rows()
#  sometext_lets_pretend_its_JSON
#1                            999
#2                            999
#3                            999
#4                            999
#5                            999
#6                            999

Flatten JSON list into data frame

1 Answers1