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reqvsrvest

MIT 42 1 3,977
58.1 thousand (month) Jun 08 2023 v3.43.1(25 days ago)
1,455 1 17 MIT
1.0.4(1 year, 7 months ago) Nov 22 2014 629.3 thousand (month)

The Go library "req" is a simple and easy-to-use library for making HTTP requests in Go. It is designed to make working with HTTP requests as simple as possible, by providing a clean and consistent API for handling various types of requests, including GET, POST, PUT, and DELETE.

One of the key features of req is its support for handling JSON data. The library automatically serializes and deserializes JSON data, making it easy to work with JSON data in your Go applications. Additionally, it supports multipart file uploads and automatic decompression of gzip and deflate encoded responses.

req also includes a number of convenience functions for working with common HTTP request types, such as sending GET and POST requests, handling redirects, and setting headers and query parameters. The library can also be easily extended with custom middleware and request handlers.

Overall, req is a powerful and flexible library that makes it easy to work with HTTP requests in Go. It is well-documented and actively maintained, making it a great choice for any Go project that needs to work with HTTP requests.

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

Example Use


req.DevMode() //  Use Client.DevMode to enable debugging details

// There are 2 ways to use req (like many other http clients)
// First way is to create a persistent session client:
client := req.C(). // defaults like timeout and headers can be set for the whole session
    SetUserAgent("my-custom-client").
    SetTimeout(5 * time.Second)
// defaults can be overriden and extended in each request
resp, err := client.R(). // Use R() to create a request and set with chainable request settings.
    SetHeader("Accept", "application/vnd.github.v3+json").
    SetPathParam("username", "imroc").
    SetQueryParam("page", "1").
    SetResult(&result). // Unmarshal response into struct automatically if status code >= 200 and <= 299.
    SetError(&errMsg). // Unmarshal response into struct automatically if status code >= 400.
    EnableDump(). // Enable dump at request level to help troubleshoot, log content only when an unexpected exception occurs.
    Get("https://api.github.com/users/{username}/repos")

// Alternatively, it can be used as is without establishing a client

resp := client.Get("https://api.github.com/users/{username}/repos"). // Create a GET request with specified URL.
    SetHeader("Accept", "application/vnd.github.v3+json").
    SetPathParam("username", "imroc").
    SetQueryParam("page", "1").
    SetResult(&result).
    SetError(&errMsg).
    EnableDump().
    Do() // Send request with Do.
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"

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