WEB-Scraping-practical-guide

Web Scraping — Practical Guide

A clear and concise guide on modern web scraping.   ---

1. What is Web Scraping?

**Web scraping** is the automated process of extracting data from websites using software or scripts that retrieve and parse HTML content.

Main Steps of web scarpping

1. **Fetching** — The scraper requests the page HTML.  
2. **Parsing** — Extract relevant elements from the HTML/DOM.  
3. **Storing** — Save extracted data in CSV, JSON, or a database.

There are several programming languages that can be used for web scraping. Below, I’ve listed them along with a brief description of their commonly used libraries and tools for each language.

Language Strengths Common Libraries / Tools
Python Easy syntax, rich ecosystem Requests, BeautifulSoup, Scrapy,
Selenium, Playwright, pandas    
JavaScript Browser-like scraping Puppeteer, Cheerio, Axios, Playwright
Java High performance at scale Jsoup, Selenium
PHP Server-side scripting; small projects cURL, DOMDocument
Go Fast, lightweight concurrency colly, goquery
R Data science oriented rvest, httr
C# (.NET) Enterprise and Windows apps HtmlAgilityPack, Selenium

Although there are several languages available for web scraping, Python is the most popular and powerful one. That’s why I prefer using Python for scraping. The reasons for my choice are listed below.

- Simple syntax — easy to learn and fast to prototype.  
- Extensive libraries for HTTP, parsing, browser automation, and data handling.  
- Excellent tools for automation and integration (pandas, NumPy, DB drivers).  
- Large community and well-documented ecosystem.

4. Pre-scrape Analysis of the Exeficiq Website — Checklist

Pre-Scrape Analysis — Essential Checklist

- Determine rendering type: Identify whether the site is Static, Dynamic (CSR), SSR, or SPA.

- Inspect HTML structure: Right-click → Inspect → Elements to locate the data you want to extract.

- Check the Network tab: In the XHR or Fetch section, look for API calls that return JSON — these often contain raw data.

- Check authentication requirements: Note if login, tokens, or cookies are required for access.

- Review robots.txt: See which paths are allowed or disallowed for crawlers.

- Identify pagination patterns: Detect if the site uses lazy loading or infinite scroll.

- Plan your storage schema: Choose between CSV, JSON, Relational DB, or NoSQL (e.g.MongoDB) based on your needs.

5. How to Detect Page Rendering Type ?

Knowing whether a website is Static, CSR, SSR, or SPA helps you choose the most effective scraping method.

Step-by-Step Process:

1. Open Developer Tools: Press F12 or Right-click → Inspect.

2. Check the Elements tab:

    - If the desired content (text, images, etc.) is visible directly in the HTML, the page is likely Static or SSR.

3. Disable JavaScript:

    - Click the three dots  in the top-right corner of DevTools.
    - Open Run Command (or Command Menu) and type “Disable JavaScript”.
    - Press Enter to disable it.

4. Reload the page:

    - If the page still loads fully and shows content → it’s Static or SSR.
    - If the page loads partially or stays blank → it’s CSR (Client-Side Rendered) or a SPA (Single Page Application).

6. Common Anti-bot Protections (Awareness Only)

Protection Description
robots.txt Suggests crawler-friendly paths — follow it as etiquette.
Rate limiting Throttle requests; use delays or paginated APIs.
IP blocking Avoid excessive requests; use legitimate data sources.
CAPTCHA Prevents automation — do not bypass.
JavaScript challenges Requires real browser context (e.g. Playwright).
Fingerprinting Detects non-human patterns or bot signals.

Important: Never bypass security, authentication, or CAPTCHA.
Always use legal APIs or authorized partnerships where available.


7. Which Library to Use?

Use Case Recommended Tool
Static pages, simple scraping requests + BeautifulSoup
Large-scale crawling Scrapy
JS-heavy sites Playwright
Browser automation (legacy) Selenium
Async scraping httpx, aiohttp

8. Why are different tools used, and what are their mechanisms for web scraping?

Here we discuss about a comparative overview of popular web scraping tools — Selenium, BeautifulSoup, Scrapy, and Playwright.
It explains their strengths, weaknesses, use cases, and real-life analogies to help you decide which one to use for your specific project.

BeautifulSoup

Use Case:
Simple HTML parsing, small projects, or static pages.

Key Features:

Advantages:

Limitations:

Real-life Analogy:
If BeautifulSoup is a skilled librarian who can find and organize information in already opened books, it still depends on someone else to bring the book.


Selenium

Use Case:
Automated browsing, dynamic websites, and web apps that heavily depend on JavaScript.

Key Features:

Advantages:

Limitations:

Real-life Analogy:
If Selenium is an old manual robot that can do everything like a human — open pages, click buttons, type text — it’s powerful but slow and noisy.


Scrapy

Use Case:
Large-scale scraping, crawling multiple pages, and managing structured data pipelines.

Key Features:

Advantages:

Limitations:

Real-life Analogy:
If Scrapy is a factory with many robotic arms, it’s designed for large-scale data extraction — efficient, systematic, but requires setup and structure.


Playwright

Use Case:
Modern web automation, handling complex and dynamic pages efficiently.

Key Features:

Advantages:

Limitations:

Real-life Analogy:
If Selenium is an old manual robot, Playwright is a fleet of modern smart robots — faster, quieter, can multitask, and understand complex web pages better.