解析错误:在尝试解析数据框中的JSON列时"追踪垃圾"

Question

我有一个看起来像这样的日志文件.

我试图通过以下方式解析Message列中的JSON :

library(readr)
library(jsonlite)

df <- read_csv("log_file_from_above.csv")
fromJSON(as.character(df$Message))

但是,我遇到了以下错误:

Error: parse error: trailing garbage
          "isEmailConfirmed": false  } {    "id": -1,    "firstName": 
                     (right here) ------^

我怎样才能摆脱"尾随垃圾"？

Answer 1

fromJSON()不是"应用"字符向量,它试图将它全部转换为数据帧.你可以试试

purrr::map(df$Message, jsonlite::fromJSON)

@Abdou提供的内容或

jsonlite::stream_in(textConnection(gsub("\\n", "", df$Message)))

后两者将创建数据帧.第一个将创建一个列表,您可以添加为列.

您可以使用最后一个方法dplyr::bind_cols创建包含所有数据的新数据框:

dplyr::bind_cols(df[,1:3],
                 jsonlite::stream_in(textConnection(gsub("\\n", "", df$Message))))

@Abdou也建议使用几乎纯粹的基本R解决方案:

cbind(df, do.call(plyr::rbind.fill, lapply(paste0("[",df$Message,"]"), function(x) jsonlite::fromJSON(x))))

完整,有效,工作流程:

library(dplyr)
library(jsonlite)

df <- read.table("http://pastebin.com/raw/MMPMwNZv",
                 quote='"', sep=",", stringsAsFactors=FALSE, header=TRUE)

bind_cols(df[,1:3], stream_in(textConnection(gsub("\\n", "", df$Message)))) %>%
  glimpse()
## 
 Found 3 records...
 Imported 3 records. Simplifying into dataframe...
## Observations: 3
## Variables: 19
## $ Id                  <int> 35054, 35055, 35059
## $ Date                <chr> "2016-06-17 19:29:43 +0000", "2016-06-17 1...
## $ Level               <chr> "INFO", "INFO", "INFO"
## $ id                  <int> -2, -1, -3
## $ ipAddress           <chr> "100.100.100.100", NA, "100.200.300.400"
## $ howYouHearAboutUs   <chr> NA, "Radio", NA
## $ isInterestedInOffer <lgl> TRUE, FALSE, TRUE
## $ incomeRange         <int> 60000, 1, 100000
## $ isEmailConfirmed    <lgl> FALSE, NA, TRUE
## $ firstName           <chr> NA, "John", NA
## $ lastName            <chr> NA, "Smith", NA
## $ email               <chr> NA, "john.smith@gmail.com", NA
## $ city                <chr> NA, "Smalltown", NA
## $ birthDate           <chr> NA, "1999-12-10T05:00:00Z", NA
## $ password            <chr> NA, "*********", NA
## $ agreeToTermsOfUse   <lgl> NA, TRUE, TRUE
## $ visitUrl            <chr> NA, NA, "https://www.website.com/?purpose=X"
## $ isIdentityConfirmed <lgl> NA, NA, FALSE
## $ validationResults   <lgl> NA, NA, NA