将JSON列表中的分级项映射到R中的数据框

library(jsonlite)
json_data <- '[{"id": 1, "name": "A", "parent_id": null}, {"id": 2, "name": "B", "parent_id": 1}, {"id": 3, "name": "C", "parent_id": 2}]'
list_data <- fromJSON(json_data)

df <- data.frame(id = numeric(),
                 name = character(),
                 parent_id = numeric(),
                 stringsAsFactors = FALSE)

for (i in 1:length(list_data)) {
  df <- rbind(df, list_data[[i]])
}

df <- merge(df, df, by.x = "parent_id", by.y = "id", all.x = TRUE, suffixes = c("", "_parent"))