ralgervsexcon
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.
Excon is a Ruby library for making HTTP requests. It is designed to be fast and efficient, and is often used as a building block for other Ruby libraries and frameworks.
One of the main features of Excon is its support for persistent connections, which allows it to reuse the same connection for multiple requests, reducing the overhead of establishing a new connection for each request.
Excon also supports streaming requests and responses, which allows you to read or write data to the server incrementally, without having to load the entire response into memory at once.
Example Use
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
require 'excon'
# GET requests
response = Excon.get('https://jsonplaceholder.typicode.com/posts/1')
puts response.body
puts response.status
puts response.headers
# POST requests
response = Excon.post('https://jsonplaceholder.typicode.com/posts',
:body => { :title => 'foo', :body => 'bar', :userId => 1 }.to_json,
:headers => { 'Content-Type' => 'application/json' } )
puts response.body