Xpathでこのエラーを解決するには

Question

FBのためのホルダーテーブル（ "Direct Holders（Forms 3 and 4）"）を抽出しようとしました。Xpath関数をテーブルのChromeの "Inspect element"エラーが発生しました。このエラーはどうやって解決できますか？

url = "http://finance.yahoo.com/quote/FB/holders?p=FB" 
doc = htmlTreeParse(url, useInternalNodes = T) 
tab_nodes = xpathApply(doc, "//*[@id="main-0-Quote-Proxy"]/section/div[2]/section/div/section/div[3]/div[2]/div[2]/table") 

Error: unexpected symbol in "tab_nodes = xpathApply(doc, "//*[@id="main"

Answer 1

それがXHRリクエストで取得したデータから構築された動的なコンテンツですので、あなたはそれをこすりすることはできません。開発者ツールを開いた状態で、[ネットワーク]タブに移動し、[XHR]を選択してページを更新します。いくつかのURLが表示されます.1つはJSONで必要なデータです。

library(dplyr) 
library(httr) 
library(purrr) 
library(readr) 

URL <- "https://query2.finance.yahoo.com/v10/finance/quoteSummary/FB?lang=en-US&region=US&modules=institutionOwnership%2CfundOwnership%2CmajorDirectHolders%2CmajorHoldersBreakdown%2CinsiderTransactions%2CinsiderHolders%2CnetSharePurchaseActivity&corsDomain=finance.yahoo.com" 
res <- GET(URL) 
dat <- content(res) 
df <- map_df(dat$quoteSummary$result[[1]]$majorDirectHolders$holders, ~as.list(unlist(.))) 
glimpse(df) 
## Observations: 10 
## Variables: 22 
## $ maxAge     <int> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 
## $ name      <chr> "KOUM JAN", "SANDBERG SHERYL", "ZUCKERBERG MAR... 
## $ relation     <chr> "Director", "Officer", "Officer", "Officer", "... 
## $ url      <chr> "http://biz.yahoo.com/t/28/9464.html", "http:/... 
## $ transactionDescription <chr> "Automatic Sale", "Sale", "Automatic Sale", "A... 
## $ latestTransDate.raw  <int> 1471824000, 1471219200, 1471478400, 1471219200... 
## $ latestTransDate.fmt  <date> 2016-08-22, 2016-08-15, 2016-08-18, 2016-08-1... 
## $ positionDirect.raw  <int> 2576396, 4593776, NA, 651044, 648776, 420525, ... 
## $ positionDirect.fmt  <dbl> 2.58, 4.59, NA, 651.04, 648.78, 420.52, 222.19... 
## $ positionDirect.longFmt <dbl> 2576396, 4593776, NA, 651044, 648776, 420525, ... 
## $ positionDirectDate.raw <int> 1447632000, 1471219200, NA, 1471219200, 143164... 
## $ positionDirectDate.fmt <date> 2015-11-16, 2016-08-15, NA, 2016-08-15, 2015-... 
## $ positionIndirect.raw  <int> 38729593, 23824, 3756744, NA, NA, NA, NA, 2144... 
## $ positionIndirect.fmt  <dbl> 38.73, 23.82, 3.76, NA, NA, NA, NA, 214.41, 17... 
## $ positionIndirect.longFmt <dbl> 38729593, 23824, 3756744, NA, NA, NA, NA, 2144... 
## $ positionIndirectDate.raw <int> 1471824000, 1444348800, 1471478400, NA, NA, NA... 
## $ positionIndirectDate.fmt <date> 2016-08-22, 2015-10-09, 2016-08-18, NA, NA, N... 
## $ positionSummary.raw  <int> 41305989, 4617600, NA, NA, NA, NA, NA, 218185,... 
## $ positionSummary.fmt  <dbl> 41.31, 4.62, NA, NA, NA, NA, NA, 218.19, 185.3... 
## $ positionSummary.longFmt <dbl> 41305989, 4617600, NA, NA, NA, NA, NA, 218185,... 
## $ positionSummaryDate.raw <int> 1471824000, 1471219200, NA, NA, NA, NA, NA, 14... 
## $ positionSummaryDate.fmt <date> 2016-08-22, 2016-08-15, NA, NA, NA, NA, NA, 2...