如何解析 R 中的特定实体？

Question

我有 JSON 文件，其中包含事件和这些事件中的日志，示例如下所示：

{
  "sessionEvents": [
    {
      "u": "BC0F6A3A2840B6F48386BABC5F34B480BA4F9929",
      "v": "0.1.0",
      "dv": "Unidentified",
      "t": 1462924115818,
      "uid": "",
      "len": 148012,
      "by": 0,
      "g": "U",
      "cy": "PH",
      "cr": "Unknown",
      "dm": "O+ Xfinit",
      "lat": 0.0,
      "lon": 0.0,
      "l": [
        {
          "e": "100_SESSION_START",
          "o": 24,
          "d": 147988,
          "p": {
            "User_Timezone": "-08:00",
            "Session_nb": "0",
            "Energy_Balance": "89",
            "Global_Playtime": "0",
            "Device_id": "75e64b654c01949",
            "Game_Language": "en",
            "Connection_Type": "WIFI",
            "User_Country": "US",
            "Push_Impact": "None"
          }
        },
        {
          "e": "008_TUTORIAL_STEP_OTHER",
          "o": 7561,
          "d": 0,
          "p": {
            "Screen_id": "scene_screen",
            "Misclicks": "0",
            "Tutorial_Step": "19",
            "Average_Time_Per_Frame": "0",
            "Total_Time": "0"
          }
        }
      ]
    },
    {
      "u": "C950FC733D883E11E36E15A705E05A3CC7748C3A",
      "v": "0.1.0",
      "dv": "OPPO Mirror 5",
      "t": 1462908916463,
      "uid": "",
      "len": 5368,
      "by": 0,
      "g": "U",
      "cy": "PH",
      "cr": "Unknown",
      "dm": "A51w",
      "lat": 0.0,
      "lon": 0.0,
      "l": [
        {
          "e": "100_SESSION_START",
          "o": 169,
          "d": 5199,
          "p": {
            "User_Timezone": "-08:00",
            "Session_nb": "0",
            "Energy_Balance": "0",
            "Global_Playtime": "0",
            "Device_id": "d0de71513e48fba",
            "Game_Language": "en",
            "Connection_Type": "WIFI",
            "User_Country": "US",
            "Push_Impact": "None"
          }
        }
      ]
    }
  ]
}

如您所见，有一个带有事件日志的二级对象 "l" 和带有参数的第三级对象 "p"，这让我很痛苦。我正在尝试将其转换为数据框，但我只需要 table 中的“100_SESSION_START”日志值（"l" 和 "p" 名称的所有参数名称都是相同），另外，我需要添加来自更高级别对象的所有参数 - 事件（'u'、'v'、'dv'、't'...）。有谁知道如何做用户 R 吗？

upd: 结果是 table 像这样就好了 click

Answer 1

假设您已将 json 文件加载到 data 变量中

data <- fromJSON("/home/joel/tmp/input.json")

然后您可以根据需要迭代每个事件和每个事件日志：

n<-length(data$sessionEvents$u)
for (i in 1:n) { # Iterate over events
  print(data$sessionEvents$u[i])
  print(data$sessionEvents$v[i])
  print(data$sessionEvents$dv[i])
  print(data$sessionEvents$t[i])
  m<-length(data$sessionEvents$l[i][[1]]$e)
  for(j in 1:m){ # Iterate over logs
    print(data$sessionEvents$l[i][[1]]$e[j])
  }
}

希望对您有所帮助。

Answer 2

您可以使用 lapply 来做类似的事情。

topLevel <- c("u", "v", "dv", "t")
midLevel <- c("e", "o", "d")
botLevel <- c("User_Timezone", "Session_nb", "Energy_Balance", "Global_Playtime")

do.call(rbind, lapply(li[[1]], function(x) {
    do.call(rbind, lapply(x$l, function(y) {
        if(y$e == "100_SESSION_START") {
            c(y[midLevel], y$p[botLevel], x[topLevel])
        }
    }))
}))

     e                   o   d      User_Timezone Session_nb Energy_Balance Global_Playtime
[1,] "100_SESSION_START" 24  147988 "-08:00"      "0"        "89"           "0"            
[2,] "100_SESSION_START" 169 5199   "-08:00"      "0"        "0"            "0"            
     u                                          v       dv              t           
[1,] "BC0F6A3A2840B6F48386BABC5F34B480BA4F9929" "0.1.0" "Unidentified"  1.462924e+12
[2,] "C950FC733D883E11E36E15A705E05A3CC7748C3A" "0.1.0" "OPPO Mirror 5" 1.462909e+12

如何解析 R 中的特定实体？

How to parse specific entities in R?

json

r

jsonlite