在R中将一个复杂的HTML表拖放到data.frame中

我试图将维基百科关于美国最高法院法官的数据加载到R：

library(rvest)

html = html("http://en.wikipedia.org/wiki/List_of_Justices_of_the_Supreme_Court_of_the_United_States")
judges = html_table(html_nodes(html, "table")[[2]])
head(judges[,2])

[1] "Wilson, JamesJames Wilson"       "Jay, JohnJohn Jay†"             
[3] "Cushing, WilliamWilliam Cushing" "Blair, JohnJohn Blair, Jr."     
[5] "Rutledge, JohnJohn Rutledge"     "Iredell, JamesJames Iredell"  

问题是数据格式不正确。与我在实际HTML表中看到的名称（“James Wilson”）不同，它实际上出现了两次，一次是“Lastname，Firstname”，然后是“Firstname Lastname”

原因是每一个实际上都包含一个不可见的：

<td style="text-align:left;" class="">
    <span style="display:none" class="">Wilson, James</span>
    <a href="/wiki/James_Wilson" title="James Wilson">James Wilson</a>
</td>

威尔逊，詹姆斯

对于包含数字数据的列也是如此。我猜这段额外的代码是对HTML表进行排序所必需的。但是，在尝试从R中的表中创建data.frame时，我不清楚如何删除这些跨距。

您可以使用

它并不完美，因此您可能希望改进css选择器，但它让您非常接近

可能是这样

library(XML)
library(rvest)
html = html("http://en.wikipedia.org/wiki/List_of_Justices_of_the_Supreme_Court_of_the_United_States")
judges = html_table(html_nodes(html, "table")[[2]])
head(judges[,2])
# [1] "Wilson, JamesJames Wilson"       "Jay, JohnJohn Jay†"              "Cushing, WilliamWilliam Cushing" "Blair, JohnJohn Blair, Jr."     
# [5] "Rutledge, JohnJohn Rutledge"     "Iredell, JamesJames Iredel

removeNodes(getNodeSet(html, "//table/tr/td[2]/span"))
judges = html_table(html_nodes(html, "table")[[2]])
head(judges[,2])
# [1] "James Wilson"    "John Jay†"       "William Cushing" "John Blair, Jr." "John Rutledge"   "James Iredell" 

library(XML)
library(rvest)
html = html("http://en.wikipedia.org/wiki/List_of_Justices_of_the_Supreme_Court_of_the_United_States")
judges = html_table(html_nodes(html, "table")[[2]])
head(judges[,2])
# [1] "Wilson, JamesJames Wilson"       "Jay, JohnJohn Jay†"              "Cushing, WilliamWilliam Cushing" "Blair, JohnJohn Blair, Jr."     
# [5] "Rutledge, JohnJohn Rutledge"     "Iredell, JamesJames Iredel

removeNodes(getNodeSet(html, "//table/tr/td[2]/span"))
judges = html_table(html_nodes(html, "table")[[2]])
head(judges[,2])
# [1] "James Wilson"    "John Jay†"       "William Cushing" "John Blair, Jr." "John Rutledge"   "James Iredell"