Scrape the web — Advance Techniques
If you are reading this to learn “How to Scrap?”. Then definitely you know about what is Scraping. If you are a new guy to the field and wondering what the hell is this thing, then get some knowledge about Scraping first. Here is a little introduction about what is scraping? why do we need to use it? and how can we use it?.
What is Web Scraping?
Web Scraping(also termed Screen Scraping, Web Data Extraction, Web Harvesting, etc.) is a technique to extract huge amounts of data from websites whereby the data is extracted and saved to a local file in your computer or to a database table. This technique mostly focuses on the transformation of unstructured data (HTML format) on the web into structured data (database or spreadsheet).
Why do people need to Scrape data from websites?
Well, Data displayed by most websites can only be viewed using a web browser. They do not offer the functionality to save a copy of that data for personal use. The only option then is to manually copy and paste the data — a very tedious job which can take many hours or sometimes days to complete. Web Scraping is the technique of automating this process so that instead of manually copying the data from websites, the Web Scraping software will perform the same task within a fraction of the time.
How do we Scrape the Data?
Here, we are back to our Topic. There are bundles of Programming languages available in the world, that send GET and POST requests to the server and can manipulate the response according to our needs. Most of the popular Programming Language used for Web Scraping is Python. Many developers wrote too many modules for it so they can easily do things just by importing them. For Scraping, we use the following modules in Python.
- bs4
- requests
- scrapy
- selenium
- lxml
- others
I am not here to teach you what the modules can do. I am here to show you, what techniques can we use to scrape the data a normal person cannot achieve through a simple Python program.
When you want to scrap the web, Make sure you focus on the following things before losing hope.
Search for the API
The priority is to search for API on the web by Analyzing its traffic, reading source code and googling stuff about the web.
Here is a technique you can use to search for an API of a website.
Analyze the Traffic
Look into the Network Tab of the browser in the Developer Tools while browsing the site or making requests. Filter the requests by useful strings or analyze one by one URL.
By analyzing the Traffic or getting API, your work will be minimized by half. You can work peacefully because an API offers JSON which is too easy to handle by Python.
Add Specific Headers
Some websites check for specific headers and then give a response to the user. Same as above, analyze the web traffic through Network Tab and check which headers are sent to the website in the request headers section. To test it properly, You need to Open an Incognito Tab and View the website source code instead of the rendering page to check for headers protection. After doing that check the response and analyze it well.
Copy as Curl
Sometimes you can’t figure out what headers need to be imported or there are too many inputs that you can’t figure out which one to copy and how or even you include all the headers but it still won’t work. There you need to copy the request from the Network Tab as CURL and convert that CURL request into Python code using a Lovely Tool: https://curl.trillworks.com/
Use Session
Use Session class of the python module ‘requests’. It will help you store the headers returned by the server and the cookies automatically. You don’t need to parse the cookies and headers manually to each request.
There are many ways to scrape the web, but these were some of them I use the most. Hope you find it helpful, If you need help regarding any python problem, just ping me and I will help you out.
Do share if you like it.
print(“Python is my Favourite Language”)
Moreover, I am a TOP rated freelancer on Upwork. If you want to hire me, contact me on my email ijazkhan095@gmail.com. Thanks
