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ralgervsdude

MIT 3 1 153
1.2 thousand (month) Dec 22 2019 2.2.4(3 years ago)
411 2 24 MIT
0.1.3(8 months ago) Feb 20 2022 27 (month)

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.

Dude (dude uncomplicated data extraction) is a very simple framework for writing web scrapers using Python decorators. The design, inspired by Flask, was to easily build a web scraper in just a few lines of code. Dude has an easy-to-learn syntax.

The simplest web scraper will look like this:

from dude import select


@select(css="a")
def get_link(element):
    return {"url": element.get_attribute("href")}

dude supports multiple parser backends: - playwright
- lxml
- parsel - beautifulsoup - pyppeteer - selenium

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
from dude import select

"""
This example demonstrates how to use Parsel + async HTTPX
To access an attribute, use:
    selector.attrib["href"]
You can also access an attribute using the ::attr(name) pseudo-element, for example "a::attr(href)", then:
    selector.get()
To get the text, use ::text pseudo-element, then:
    selector.get()
"""


@select(css="a.url", priority=2)
async def result_url(selector):
    return {"url": selector.attrib["href"]}


# Option to get url using ::attr(name) pseudo-element
@select(css="a.url::attr(href)", priority=2)
async def result_url2(selector):
    return {"url2": selector.get()}


@select(css=".title::text", priority=1)
async def result_title(selector):
    return {"title": selector.get()}


@select(css=".description::text", priority=0)
async def result_description(selector):
    return {"description": selector.get()}


if __name__ == "__main__":
    import dude

    dude.run(urls=["https://dude.ron.sh"], parser="parsel")

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