快速解析 html 的最佳实践是什么?

本文介绍了快速解析 html 的最佳实践是什么?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我是 Swift 新手.我需要在 Swift iOS 项目中使用 Python 的 BeautifulSoup 之类的东西.准确地说，我需要获取以 ".txt" 结尾的的所有 href.我应该采取哪些步骤?

有几个使用 Swift 和 Objective-C 的不错的 HTML 解析库代码>如下所示:

hpple
NDHpple
Kanna(旧的 Swift-HTML-Parser)
Fuzi
SwiftSoup
姬

看看上面发布的四个库中的以下示例，主要使用XPath 2.0:

hpple:

let data = NSData(contentsOfFile: path)让 doc = TFHpple(htmlData: 数据)if let elements = doc.searchWithXPathQuery("//a/@href[ends-with(.,'.txt')]") as?[TFHppleElement] {对于元素中的元素{打印(元素.内容)}}

NDHpple:

let data = NSData(contentsOfFile: path)！让 html = NSString(data: data, encoding: NSUTF8StringEncoding)！让 doc = NDHpple(HTMLData: html)if let elements = doc.searchWithXPathQuery("//a/@href[ends-with(.,'.txt')]") {对于元素中的元素{println(element.children?.first?.content)}}

Kanna(Xpath 和 CSS 选择器):

let html = "

Fuzi(Xpath 和 CSS 选择器):

let html = "

ends-with 函数是 Xpath 2.0 的一部分.

SwiftSoup(CSS 选择器):

做{让 doc: Document = try SwiftSoup.parse("...")let links: Elements = try doc.select("a[href]")//a with href让 pngs: Elements = try doc.select("img[src$=.png]")//以 src 结尾的 img .png让刊头:元素?= 尝试 doc.select("div.masthead").first()//带有 class=masthead 的 div让结果链接:元素?= try doc.select("h3.r > a")//在 h3 之后直接 a} catch Exception.Error(let type, let message){打印(消息)} 抓住 {打印(错误")}

姬 (XPath):

let jiDoc = Ji(htmlURL: URL(string: "http://www.apple.com/support")!)let titleNode = jiDoc?.xPath("//head/title")?.firstprint("title: (titleNode?.content)")//title: Optional("Apple 官方支持")

希望对你有帮助.

I'm a Swift newbie. I need for something like Python's BeautifulSoup in Swift iOS project. Precisely, I need to get all href of <a> that ends with ".txt". What are the steps that I should take?

解决方案

There are several nice libraries of HTML Parsing using Swift and Objective-C like the followings:

hpple
NDHpple
Kanna( old Swift-HTML-Parser)
Fuzi
SwiftSoup
Ji

Take a look in the following examples in the four libraries posted above, mainly parsed using XPath 2.0:

let data = NSData(contentsOfFile: path)
let doc = TFHpple(htmlData: data)

if let elements = doc.searchWithXPathQuery("//a/@href[ends-with(.,'.txt')]") as? [TFHppleElement] {
   for element in elements {
       println(element.content)
   }
}

let data = NSData(contentsOfFile: path)!
let html = NSString(data: data, encoding: NSUTF8StringEncoding)!
let doc = NDHpple(HTMLData: html)
if let elements = doc.searchWithXPathQuery("//a/@href[ends-with(.,'.txt')]") {
   for element in elements {
     println(element.children?.first?.content)
   }
}

let html = "<html><head></head><body><ul><li><input type='image' name='input1' value='string1value' class='abc' /></li><li><input type='image' name='input2' value='string2value' class='def' /></li></ul><span class='spantext'><b>Hello World 1</b></span><span class='spantext'><b>Hello World 2</b></span><a href='example.com'>example(English)</a><a href='example.co.jp'>example(JP)</a></body>"

if let doc = Kanna.HTML(html: html, encoding: NSUTF8StringEncoding) {
   var bodyNode   = doc.body

   if let inputNodes = bodyNode?.xpath("//a/@href[ends-with(.,'.txt')]") {
      for node in inputNodes {
         println(node.contents)
      }
   }
}

let html = "<html><head></head><body><ul><li><input type='image' name='input1' value='string1value' class='abc' /></li><li><input type='image' name='input2' value='string2value' class='def' /></li></ul><span class='spantext'><b>Hello World 1</b></span><span class='spantext'><b>Hello World 2</b></span><a href='example.com'>example(English)</a><a href='example.co.jp'>example(JP)</a></body>"

do {
  // if encoding is omitted, it defaults to NSUTF8StringEncoding
  let doc = try HTMLDocument(string: html, encoding: NSUTF8StringEncoding)

  // XPath queries
  for anchor in doc.xpath("//a/@href[ends-with(.,'.txt')]") {
    print(anchor.stringValue)
  }

} catch let error {
    print(error)
}

The ends-with function is part of Xpath 2.0.

do{
    let doc: Document = try SwiftSoup.parse("...")
    let links: Elements = try doc.select("a[href]") // a with href
    let pngs: Elements = try doc.select("img[src$=.png]")

    // img with src ending .png
    let masthead: Element? = try doc.select("div.masthead").first()

    // div with class=masthead
    let resultLinks: Elements? = try doc.select("h3.r > a") // direct a after h3
} catch Exception.Error(let type, let message){
    print(message)
} catch {
   print("error")
}

let jiDoc = Ji(htmlURL: URL(string: "http://www.apple.com/support")!)
let titleNode = jiDoc?.xPath("//head/title")?.first
print("title: (titleNode?.content)") // title: Optional("Official Apple Support")

I hope this helps you.

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