使用purrr重组列表

Question

当我用R和purrr清理复杂的列表时，我有以下问题。示例将清除这一点。

所需的包

library(jsonlite)
library(purrr)
library(tibble)
library(dplyr)

让我们从NHL json获取示例数据。

url <- c("https://statsapi.web.nhl.com/api/v1/game/2017010002/feed/live", "https://statsapi.web.nhl.com/api/v1/game/2017010005/feed/live")

data_list <- map(url, fromJSON)

这是一个相当复杂的列表，但最后我想要的是result，这是最后的。主要的想法是，我想有列表列与tibble在它，但tibble是由选择的向量/列从列表的不同部分创建。以下是我失败的尝试：

wrong <- tibble(
  gamepk = map_chr(data_list, c("gamePk"), .default = NA),
  home = map_chr(data_list, c("gameData", "teams", "home", "triCode"), .default = NA),
  away = map_chr(data_list, c("gameData", "teams", "away", "triCode"), .default = NA),
  test = list(tibble(event = map(data_list, c("liveData", "plays", "allPlays", "result", "event"), .default = NA),
                     x_cord = map(data_list, c("liveData", "plays", "allPlays", "coordinates", "x"), .default = NA),
                     y_cord = map(data_list, c("liveData", "plays", "allPlays", "coordinates", "y"), .default = NA)))
)

# A tibble: 2 x 4
  gamepk     home  away  test            
  <chr>      <chr> <chr> <list>          
1 2017010002 VAN   VGK   <tibble [2 x 3]>
2 2017010005 BUF   CAR   <tibble [2 x 3]>

这里有一种笨拙的方法来做这件事并纠正结果。

result <- tibble(
  gamepk = map_chr(data_list, c("gamePk"), .default = NA),
  home = map_chr(data_list, c("gameData", "teams", "home", "triCode"), .default = NA),
  away = map_chr(data_list, c("gameData", "teams", "away", "triCode"), .default = NA))

test1 <- bind_cols(event = data_list[[1]]$liveData$plays$allPlays$result$event, 
          x_cord = data_list[[1]]$liveData$plays$allPlays$coordinates$x,
          y_cord = data_list[[1]]$liveData$plays$allPlays$coordinates$y)

test2 <- bind_cols(event = data_list[[2]]$liveData$plays$allPlays$result$event, 
                  x_cord = data_list[[2]]$liveData$plays$allPlays$coordinates$x,
                  y_cord = data_list[[2]]$liveData$plays$allPlays$coordinates$y)

result$test[1] <- list(test1)
result$test[2] <- list(test2)

result

# A tibble: 2 x 4
  gamepk     home  away  test              
  <chr>      <chr> <chr> <list>            
1 2017010002 VAN   VGK   <tibble [314 x 3]>
2 2017010005 BUF   CAR   <tibble [283 x 3]>