我安装了R 3.3.1并使用了RStudio 0.99.903。我试图通过以下网址将表格读入R:https://www.fantasypros.com/nfl/rankings/consensus-cheatsheets.php
(我很清楚有一个下载按钮,但是,这对我来说不是一个选项)
去年我使用readHTMLTable函数很容易做到这一点。但是,在那个时候,该网站从使用http更改为https,这导致" XML内容不会成为XML"错误。
我尝试了这里建议的内容:get url table into a `data.frame` R-XML-RCurl
library(XML)
library(RCurl)
url <- getURL("https://www.fantasypros.com/nfl/rankings/consensus-cheatsheets.php")
df <- readHTMLTable(URL, header = T)
获取URL函数返回一个对我来说基本上没有意义的大字符串,这意味着readHTMLTable无法正常工作(我得到一个列表,有几个数据框,但这些对我来说也毫无意义。 #39;用西班牙语观察事物,我不知道他们来自哪里):
>url
[1] "\r\n<!DOCTYPE html>\n<html lang=\"en\">\n\n<head>\n <title>2016 QB Fantasy Football Rankings, QB Cheat Sheets, QB Draft / Draft Rankings</title>\n <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"description\" content=\"Don’t trust any 1 fantasy football expert? We combine their rankings into 1 Expert Consensus Ranking. Our 2016 Draft QB rankings are updated daily.\">\n<link rel=\"canonical\" href=\"https://www.fantasypros.com/nfl/rankings/qb-cheatsheets.php\" />\n\n <meta property=\"fb:pages\" content=\"184352014941166\"/>\n
它还有很多方面。
有人可以就如何让它发挥作用提出建议吗?
感谢。
答案 0 :(得分:2)
从网址
获取html文件library("httr")
library("XML")
URL <- "https://www.fantasypros.com/nfl/rankings/consensus-cheatsheets.php"
temp <- tempfile(fileext = ".html")
GET(url = URL, user_agent("Mozilla/5.0"), write_disk(temp))
解析HTML文件
doc <- htmlParse(temp)
通过选择table
元素class = "player-table"
及其子tr
元素class = 'mpb-player-'
来构建XPath查询
xpexpr <- "//table[contains(@class, 'player-table')]/tbody/tr[contains(@class, 'mpb-player-')]"
从doc获取xpath表达式的节点列表
listofTableNodes <- getNodeSet(doc, xpexpr)
listofTableNodes
使用节点列表的xmlvalues创建数据框
df <- xmlToDataFrame(listofTableNodes, stringsAsFactors = FALSE)
# alternatively xpathSApply can be used to get the same data frame
# df <- xmlToDataFrame(xpathSApply(doc, xpexpr), stringsAsFactors = FALSE)
删除空列
df <- df[, seq(1, length(df), by = 2)]
添加列名
xpexpr <- "//table[contains(@class, 'player-table')]/thead/tr/th"
listofTableNodes <- getNodeSet(doc, xpexpr)
listofTableNodes
colnames(df) <- gsub("[\r\n ]*$", '', xmlSApply(listofTableNodes, xmlValue))
head(df)
# Rank Player (Team) Pos Bye Best Worst Avg Std Dev ADP vs. ADP
# 1 1 Antonio Brown PIT WR1 8 1 5 1.3 0.8 1.0 0.0
# 2 2 Odell Beckham Jr. NYG WR2 8 1 9 3.1 1.6 2.0 0.0
# 3 3 Julio Jones ATL WR3 11 1 6 3.4 1.1 4.0 +1.0
# 4 4 Todd Gurley LA RB1 8 1 11 4.5 2.3 3.0 -1.0
# 5 5 David Johnson ARI RB2 9 1 19 6.1 3.5 6.0 +1.0
# 6 6 Adrian Peterson MIN RB3 6 1 22 7.6 3.8 5.0 -1.0