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xpathvsralger

MIT 13 2 646
58.1 thousand (month) Jun 08 2019 (a day ago)
153 1 3 MIT
2.2.4(3 years ago) Dec 22 2019 1.2 thousand (month)

xpath is a library for Go that allows you to use XPath expressions to select elements from an HTML document. It is built on top of the html package in the Go standard library, and provides a way to select elements from an HTML document using XPath expressions, which are more powerful and expressive than CSS selectors.

ralger is a small web scraping framework for R based on rvest and xml2.

It's goal to simplify basic web scraping and it provides a convenient and easy to use API.

It offers functions for retrieving pages, parsing HTML using CSS selectors, automatic table parsing and auto link, title, image and paragraph extraction.

Example Use


package main

import (
  "fmt"
  "github.com/antchfx/xpath"
  "golang.org/x/net/html"
  "strings"
)

func main() {
  // Create an HTML string
  html := `<html>
        <body>
          <div id="content">
            <p>Hello, World!</p>
            <a href="http://example.com">Example</a>
          </div>
        </body>
      </html>`

  // Parse the HTML string into a node tree
  doc, err := html.Parse(strings.NewReader(html))
  if err != nil {
    fmt.Println("Error:", err)
    return
  }

  // Compile the XPath expression
  expr, err := xpath.Compile("//p")
  if err != nil {
    fmt.Println("Error:", err)
    return
  }

  // Use the Evaluate method to select elements from the document
  nodes, err := expr.Evaluate(xpath.NodeNavigator(doc))
  if err != nil {
    fmt.Println("Error:", err)
    return
  }
  if nodes.MoveNext() {
    fmt.Println(nodes.Current().Value())
    // > Hello, World!
  }
}
library("ralger")

url <- "http://www.shanghairanking.com/rankings/arwu/2021"

# retrieve HTML and select elements using CSS selectors:
best_uni <- scrap(link = url, node = "a span", clean = TRUE)
head(best_uni, 5)
#>  [1] "Harvard University"
#>  [2] "Stanford University"
#>  [3] "University of Cambridge"
#>  [4] "Massachusetts Institute of Technology (MIT)"
#>  [5] "University of California, Berkeley"

# ralger can also parse HTML attributes
attributes <- attribute_scrap(
  link = "https://ropensci.org/",
  node = "a", # the a tag
  attr = "class" # getting the class attribute
)

head(attributes, 10) # NA values are a tags without a class attribute
#>  [1] "navbar-brand logo" "nav-link"          NA
#>  [4] NA                  NA                  "nav-link"
#>  [7] NA                  "nav-link"          NA
#> [10] NA
#

# ralger can automatically scrape tables:
data <- table_scrap(link ="https://www.boxofficemojo.com/chart/top_lifetime_gross/?area=XWW")

head(data)
#> # A tibble: 6 × 4
#>    Rank Title                                      `Lifetime Gross`  Year
#>   <int> <chr>                                      <chr>            <int>
#> 1     1 Avatar                                     $2,847,397,339    2009
#> 2     2 Avengers: Endgame                          $2,797,501,328    2019
#> 3     3 Titanic                                    $2,201,647,264    1997
#> 4     4 Star Wars: Episode VII - The Force Awakens $2,069,521,700    2015
#> 5     5 Avengers: Infinity War                     $2,048,359,754    2018
#> 6     6 Spider-Man: No Way Home                    $1,901,216,740    2021

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