[Udemy] Scrapy: Powerful Web Scraping & Crawling with Python

Складчина: [Udemy] Scrapy: Powerful Web Scraping & Crawling with Python

Опубликовано: 10/2016 Английский

Спойлер: О курсе

Scrapy is a free and open source web crawling framework, written in Python. Scrapy is useful for web scraping and extracting structured data which can be used for a wide range of useful applications, like data mining, information processing or historical archival.

Web scraping is a technique for gathering data or information on web pages. You could revisit your favorite web site every time it updates for new information. Or you could write a web scraper to have it do it for you!

Web crawling is usually the very first step of data research. Whether you are looking to obtain data from a website, track changes on the internet, or use a website API, web crawlers are a great way to get the data you need.

While they have many components, web crawlers fundamentally use a simple process: download the raw data, process and extract it, and, if desired, store the data in a file or database. There are many ways to do this, and many languages you can build your web crawler or spider in.

Before Scrapy, developers have relied upon various software packages for this job using Python such as urllib2 and BeautifulSoup which are widely used. Scrapy is a new Python package that aims at easy, fast, and automated web crawling, which recently gained much popularity.

Scrapy is now widely requested by many clients, such as jobs on freelancing platforms, and that is was one important reason for creating this course to help you enhance your skills and gain more income.

One of the main advantages of Scrapy is that it is built on top of Twisted, an asynchronous networking framework. "Asynchronous" means that you do not have to wait for a request to finish before making another one; you can even achieve that with a high level of performance. Being implemented using a non-blocking (aka asynchronous) code for concurrency, Scrapy is really efficient.

It is worth noting that Scrapy tries not only to solve the content extraction (called scraping), but also the navigation to the relevant pages for the extraction (called crawling). To achieve that, a core concept in the framework is the Spider -- in practice, a Python object with a few special features, for which you write the code and the framework is responsible for triggering it.

Scapy provides many of the functions required for downloading websites and other content on the internet, making the development process quicker and less programming-intensive. These tutorials use custom Python scripts in conjunction with Scrapy to build web crawlers and web spiders.

Even though Scrapy was originally designed for web scraping, it can also be used to extract data using APIs (such as Amazon Associates Web Services) or as a general purpose web crawler.

Что я получу от этого курса?

• Создадим веб-сканер в Scrapy
  
• Просканируем один или нескольких веб-сайтов и вытащим данные

Какова целевая аудитория?

• Этот учебник Scrapy предназначен для тех, кто знаком с Python и хочет узнать, как создать эффективный web crawler и scraper для навигации через веб-сайты и добывать содержимое из страниц, которые содержат полезную информацию.