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rvestvsrequests

MIT 17 1 1,455
629.3 thousand (month) Nov 22 2014 1.0.4(1 year, 7 months ago)
3,555 8 99 ISC
v2.0.11(11 days ago) Oct 06 2013 16.1 thousand (month)

rvest is a popular R library for web scraping and parsing HTML and XML documents. It is built on top of the xml2 and httr libraries and provides a simple and consistent API for interacting with web pages.

One of the main advantages of using rvest is its simplicity and ease of use. It provides a number of functions that make it easy to extract information from web pages, even for those who are not familiar with web scraping. The html_nodes and html_node functions allow you to select elements from an HTML document using CSS selectors, similar to how you would select elements in JavaScript.

rvest also provides functions for interacting with forms, including html_form, set_values, and submit_form functions. These functions make it easy to navigate through forms and submit data to the server, which can be useful when scraping sites that require authentication or when interacting with dynamic web pages.

rvest also provides functions for parsing XML documents. It includes xml_nodes and xml_node functions, which also use CSS selectors to select elements from an XML document, as well as xml_attrs and xml_attr functions to extract attributes from elements.

Another advantage of rvest is that it provides a way to handle cookies, so you can keep the session alive while scraping a website, and also you can handle redirections with handle_redirects

PHP library "Requests" is an HTTP library written in PHP, for making HTTP requests. It's heavily inspired by a popular Python library called Requests and aims for the same goals of simplifying HTTP client complexities.

It abstracts the complexities of making requests behind a simple API so that you can focus on interacting with services and consuming data in your application.

Requests allows you to send HTTP/1.1 HEAD, GET, POST, PUT, DELETE, and PATCH HTTP requests. You can add headers, form data, multipart files, and parameters with basic arrays, and access the response data in the same way.

Requests uses cURL and fsockopen, depending on what your system has available, but abstracts all the nasty stuff out of your way, providing a consistent API.

Features:

  • International Domains and URLs
  • Browser-style SSL Verification
  • Basic/Digest Authentication
  • Automatic Decompression
  • Connection Timeouts

Example Use


library("rvest")

# Rvest can use basic HTTP client to download remote HTML:
tree <- read_html("http://webscraping.fyi/lib/r/rvest")
# or read from string:
tree <- read_html('
<div class="products">
  <a href="/product/1">Cat Food</a>
  <a href="/product/2">Dog Food</a>
</div>
')

# to parse HTML trees with rvest we use r pipes (the %>% symbol) and html_element function:
# we can use css selectors:
print(tree %>% html_element(".products>a") %>% html_text())
# "[1] "\nCat Food\nDog Food\n""

# or XPath:
print(tree %>% html_element(xpath="//div[@class='products']/a") %>% html_text())
# "[1] "\nCat Food\nDog Food\n""

# Additionally rvest offers many quality of life functions:
# html_text2 - removes trailing and leading spaces and joins values
print(tree %>% html_element("div") %>% html_text2())
# "[1] "Cat Food Dog Food""

# html_attr - selects element's attribute:
print(tree %>% html_element("div") %>% html_attr('class'))
# "products"
require 'vendor/autoload.php';
use Requests;

// make GET request
$response = Requests::get('https://httpbin.org/get');
echo $response->status_code;

// make POST request
$data = array('name' => 'Bob', 'age' => 35);
$options = array('auth' => array('user', 'pass'));
$response = Requests::post('https://httpbin.org/post', array(), $data, $options);
echo $response->status_code;

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