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ralgervstyphoeus

MIT 3 1 165
327 (month) Dec 22 2019 2.3.0(2021-03-18 00:10:00 ago)
4,131 17 54 MIT
Oct 06 2009 1.3 million (month) 1.6.0(2026-03-10 12:58:26 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.

Typhoeus is a Ruby library that allows you to make parallel HTTP requests, which can greatly speed up the process of making multiple requests to different servers. It is built on top of the C library libcurl, which is known for its high performance and reliability.

One of the main features of Typhoeus is its ability to make parallel requests. This means that it can send multiple requests at the same time, and wait for all of them to finish before returning the results. This can greatly reduce the time it takes to make multiple requests, as it eliminates the need to wait for each request to complete before sending the next one.

In addition to its parallelism feature, Typhoeus also provides a convenient and easy-to-use Ruby interface for making HTTP requests. It supports all of the common HTTP methods (GET, POST, PUT, DELETE, etc.) and allows you to set various request options, such as headers, timeouts, and authentication. It also supports streaming responses, which allows you to process large responses piece by piece, rather than loading the entire response into memory at once.

Typhoeus is also supports HTTP/2 protocol which provides faster load times and reduced network usage. It also supports streaming which is an essential feature for large data transfer.

Typhoeus is well-documented, actively maintained, and has a large and active community of users. It is widely used in the Ruby ecosystem and is a popular choice for building high-performance web scraping and data-gathering applications.

Note that Typhoeus can also be used as an adapter in popular alternative package Faraday.

Highlights


http2asyncuses-curl

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 # GET request Typhoeus.get("www.example.com") # POST request Typhoeus.post("www.example.com/posts", body: { title: "test post", content: "this is my test"}) # make parallel requests: # hydra is a request queue manager hydra = Typhoeus::Hydra.hydra # create request object first_request = Typhoeus::Request.new("http://example.com/posts/1") # add complete callbacks first_request.on_complete do |response| # callbacks can queue new requests third_url = response.body third_request = Typhoeus::Request.new(third_url) hydra.queue third_request end second_request = Typhoeus::Request.new("http://example.com/posts/2") # queue requests: hydra.queue first_request hydra.queue second_request hydra.run # this is a blocking call that returns once all requests are complete ```

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