在R中,如何将XML节点值与公共父节点配对?
我有以下示例XML:在R中,如何将XML节点值与公共父节点配对?,r,xml,xml-parsing,R,Xml,Xml Parsing,我有以下示例XML: <body> <div class="row"> <div class="column"> <span class="title">Color</span> </div> <div class="column property">Blue</div> </div> <div class="row">
<body>
<div class="row">
<div class="column">
<span class="title">Color</span>
</div>
<div class="column property">Blue</div>
</div>
<div class="row">
<div class="column">
<span class="title">Shape</span>
</div>
<div class="column property">Square</div>
</div>
</body>
我尝试了以下脚本,但标题周围有XML标记,并且缺少属性:
library(XML)
getDetails <- function(id) {
html <- htmlTreeParse( "exampleXML.html" ,useInternal = TRUE)
xpathSApply( html , "//div[@class='row']" , function(row) {
print( xmlElementsByTagName(row, "span", recursive = TRUE) )
})
}
getDetails()
库(XML)
获取详细信息%extract\u信息
UseMethod(“xml\u find\u all”)中出错:
没有适用于“c”类对象的“xml_find_all”方法(“HTMLInternalDocument”、“HTMLInternalDocument”、“XMLInternalDocument”、“XMLAbstractDocument”)
使用
xml2
可以执行以下操作:
library(xml2) #to install use: install.packages("xml2")
library(magrittr) #to install use: install.packages("magrittr")
extract_info <- function(x){
title <- x %>% xml_find_first(".//span[@class='title']") %>% xml_text
property <- x %>% xml_find_first(".//div[@class='column property']") %>% xml_text
setNames(property, title)
}
html <- read_xml( "exampleXML.html" )
html %>% xml_find_all("//div[@class='row']") %>% extract_info
使用
xml2
可以执行以下操作:
library(xml2) #to install use: install.packages("xml2")
library(magrittr) #to install use: install.packages("magrittr")
extract_info <- function(x){
title <- x %>% xml_find_first(".//span[@class='title']") %>% xml_text
property <- x %>% xml_find_first(".//div[@class='column property']") %>% xml_text
setNames(property, title)
}
html <- read_xml( "exampleXML.html" )
html %>% xml_find_all("//div[@class='row']") %>% extract_info
如果XML格式正确(即元素顺序不变),则可以执行以下操作:
library(xml2)
library(purrr)
doc <- read_xml(txt)
vals <- xml_text(xml_find_all(doc, ".//*[@class='title' or @class='column property']"))
map_chr(seq(1, length(vals), by=2), ~sprintf("%s = %s", vals[.], vals[.+1])) %>%
cat(sep="\n")
库(xml2)
图书馆(purrr)
doc如果XML格式正确(即元素顺序不变),则可以执行以下操作:
library(xml2)
library(purrr)
doc <- read_xml(txt)
vals <- xml_text(xml_find_all(doc, ".//*[@class='title' or @class='column property']"))
map_chr(seq(1, length(vals), by=2), ~sprintf("%s = %s", vals[.], vals[.+1])) %>%
cat(sep="\n")
库(xml2)
图书馆(purrr)
doc考虑使用嵌套的xpathsaply()
,其中外部循环跨行迭代,以解析每行标题和属性的对应值:
考虑使用嵌套的xpathsaply()
,其中外部循环跨行迭代,以解析每行标题和属性的对应值:
我发现错误:找不到函数“%>%”
。我试图从RStudio>Tools>install Packages…>xml2。还将库(xml2)
添加到脚本的开头。不走运。我在我的问题上加了“也不走运:”一节。你能看一下并更新一下你的答案吗?你自己想出来的。对不起,我的回答有一半是完整的。诀窍是通过read_xml
读取文件(与rvest
不同,xml2
更方便的包装器)xml2
不导入magrittr::%%>%%
为默认值。我得到错误:找不到函数“%%>”
。我试图从RStudio>Tools>install Packages…>xml2。还将库(xml2)
添加到脚本的开头。不走运。我在我的问题上加了“也不走运:”一节。你能看一下并更新一下你的答案吗?你自己想出来的。对不起,我的回答有一半是完整的。诀窍是通过read_xml
读取文件,并且(与rvest
不同,xml2
更方便的包装器)默认情况下xml2
不会导入magrittr::%%>%
。
library(xml2)
library(purrr)
doc <- read_xml(txt)
vals <- xml_text(xml_find_all(doc, ".//*[@class='title' or @class='column property']"))
map_chr(seq(1, length(vals), by=2), ~sprintf("%s = %s", vals[.], vals[.+1])) %>%
cat(sep="\n")
library(XML)
example_html <- paste0('<body>',
' <div class="row">',
' <div class="column">',
' <span class="title">Color</span>',
' </div>',
' <div class="column property">Blue</div>',
' </div>',
' <div class="row">',
' <div class="column">',
' <span class="title">Shape</span>',
' </div>',
' <div class="column property">Square</div>',
' </div>',
'</body>')
doc <- htmlTreeParse(example_html, useInternal = TRUE)
columns <- xpathSApply(doc, "//div[@class='row']", function(row){
title <- xpathSApply(row, "div[@class='column']/span", xmlValue)
property <- xpathSApply(row, "div[@class='column property']", xmlValue)
setNames(gsub(" ", "", property), gsub(" ", "", title)) # GSUB TO STRIP WHITESPACE
})
columns <- setNames(property, title)
columns
# Color Shape
# "Blue" "Square"
title <- xpathSApply(doc, "//div[@class='column']/span", xmlValue)
property <- xpathSApply(doc, "//div[@class='column property']", xmlValue)
columns <- setNames(property, title)
columns
# Color Shape
# "Blue" "Square"