How to Scrape Websites with Python
Is there any simple way to extract data from a web page? Yes. Web scraping is one such effective method. In case you are a beginner to this word, this post can get you familiar with this technique.
What is Web Scraping? “Web Scraping is a software technique for extracting information from the website.� This technique uses powerful tools and software to extract information from targeted websites. This technique is also called web data extraction, web data mining and web harvesting. Web scraping aims at transforming the unstructured data on the web into a structured format. You can store and analyze the formatted data in a simpler way. You can also access it in a centralized database or a spreadsheet.
Every year, more businesses are adopting these tools. These can promote advertising initiatives and Business Intelligence (BI).
Use of Web Scraping The best use of web scraping tool is mining a surplus amount of data. For instance, when you search for online deals like hotels, airline tickets, railway bookings, etc. When the ticket sales go live, a Python script can scrape the website. It can use a bot and purchase the best ticket deals for you. This script can do wonders. From extracting data smartly and efficiently than humans, it is capable of generating multiple requests simultaneously.
Web Scraping through API and Python script Some websites make life simpler in many ways. They offer Application Programming Interface (API) which enables you to download data. The famous microblogging site, Twitter and even Rotten Tomatoes provide API to easily access data. But some web pages do not provide an API. Here, you can scrape data using web scraping Python script. To scrape web data, two popular Python modules are useful. â—? Beautifulsoup and Request library â—? Urllib Beautifulsoup: This incredible tool can pull out information from any webpage. You can use it to extract lists, tables, and paragraph. You can also apply filters to extract information from various web pages. You can read the documentation available online.
Urllib2: This Python module can fetch URLs. It defines classes and methods to help with URL actions. It includes URL redirections, authentication, cookies, etc. Urllib2 is a library in Python 2. It is present by default so there is no need to install it. You can also use it in Python 3. Read also: Answering Why, What, and How of Python Web Scraping?
Here is how you can start with web scraping using Python script. Step 1: HTML Basics The first step to start with understands the HTML Basics. Scraping is all about playing with the HTML tags. So, it is important to understand the basics of HTML, to begin with. The structure is simple. Every web page structure starts with a <html> root tag. Then comes the <head> tag. The page includes the headings, title, and other Meta information tags. The <body> tag contains the actual content of the web page. The different header levels are <h1>, <h2>, <h3>, <h4>, <h5> and <h6>. Every HTML structure ends with an enclosing <html> tag. Step 2: Search the URL for scraping Not all websites and web pages can undergo scraping. Some websites are protected to prohibit scraping and other related techniques. So, before you start scraping a website or a web page, make sure to check the rules first. The robots.txt file in the website contains information about the scraping rules. You can search the robots.txt file by adding /robots.txt to the domain the site. Then, get the URL and use the basics of HTML to start scraping data.
Step 3: Identify the structure of the sites HTML Once you have got the site to perform scraping, you can use the developer tools available in the browser. You can enable this option on inspecting, the context menu available on right click. You can also press the F12 key to inspect the web page. This helps you inspect the HTML structure of the site. This is essential as you will have to work with certain HTML elements like class and IDs. You can easily identify the elements and scrape the data within. Hope this gives you a basic understanding of web scraping. Understand the methods and practice this before effectively scraping and collecting data. Source: https://www.3idatascraping.com/scrape-websites-python.php