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ralgervsxpath

MIT 3 1 165
327 (month) Dec 22 2019 2.3.0(2021-03-18 00:10:00 ago)
739 2 18 MIT
Jun 08 2019 58.1 thousand (month) v1.3.6(2026-02-23 07:10:29 ago)

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.

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.

Example Use


```r 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 #> #> 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 ```
```go package main import ( "fmt" "github.com/antchfx/xpath" "golang.org/x/net/html" "strings" ) func main() { // Create an HTML string html := `

Hello, World!

Example
` // 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! } } ```

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