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Web Crawler

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By Diogo Lages
3 min read
Web Crawler

A GUI-based Python tool for crawling websites, managing proxies, respecting robots.txt rules, and exporting data in HTML, JSON, or CSV formats.

Web Crawler Repository

Features

  • GUI Interface: A user-friendly graphical interface for configuring and controlling the crawler.
  • Robots.txt Compliance: Automatically checks and respects website crawling rules defined in robots.txt.
  • Proxy Management: Supports proxy rotation to avoid IP blocking during large-scale crawls.
  • URL Filtering: Includes and excludes URLs based on customizable patterns and domain restrictions.
  • Real-Time Statistics: Displays live metrics such as pages crawled, memory usage, queue size, and errors.
  • Data Visualization: Provides dynamic graphs for crawl speed, memory usage, and URLs in the queue.
  • Export Options: Export crawled data in HTML, JSON, or CSV formats for further analysis.
  • Pause/Resume/Stop: Full control over the crawling process with pause, resume, and stop functionality.
  • Concurrency: Configurable number of concurrent workers for efficient crawling.

How It Works

The Enhanced Web Crawler is a Python-based desktop application designed to extract structured data from websites while adhering to ethical crawling practices. Here’s how it works:

  1. Input Configuration:
    • Enter the starting URL, maximum depth, and other settings like the number of concurrent workers and rate limits.
    • Add include/exclude URL patterns to filter which pages should be crawled.
  2. Crawling Process:
    • The tool checks robots.txt compliance before crawling any page.
    • It uses proxies (if configured) to rotate IPs and avoid being blocked.
    • URLs are processed concurrently using a thread pool, ensuring efficient crawling.
  3. Data Extraction:
    • Extracts metadata such as page titles, links, and timestamps.
    • Stores the crawled data in memory for real-time updates and visualization.
  4. Monitoring and Export:
    • Real-time statistics and visualizations help monitor the crawling process.
    • Once crawling is complete, export the results in HTML, JSON, or CSV formats for further analysis.

Code Structure

The project is organized into modular components for clarity and maintainability:

  • crawler/: Core functionality for crawling, proxy management, robots.txt parsing, and statistics tracking.
    • proxy_manager.py: Manages proxy rotation.
    • robots.py: Handles robots.txt compliance.
    • stats.py: Tracks crawling statistics.
    • url_filter.py: Filters URLs based on patterns and domains.
  • gui/: Implements the graphical user interface.
    • dashboard.py: Displays real-time statistics and logs.
    • visualization.py: Provides dynamic graphs for monitoring the crawl process.
  • webcrawler.py: Entry point of the application, initializes the GUI and starts the crawler.

Interface

The interface includes:

  • Crawler Tab: Configure settings, start/pause/stop crawling, and view status.

Interface 1 Screenshot

  • Dashboard Tab: Monitor real-time statistics and logs.

Interface 2 Screenshot

  • Visualization Tab: View dynamic graphs for crawl speed, memory usage, and URLs in the queue.

Interface 3 Screenshot

Future Enhancements

  • Advanced Export Options: Support additional export formats like XML or Excel.
  • Improved Proxy Handling: Add support for authenticated proxies and automatic proxy fetching.
  • Database Integration: Store crawled data directly in a database for large-scale projects.
  • Enhanced Visualizations: Add more detailed graphs and analytics for crawled data.
  • Error Recovery: Implement automatic retry mechanisms for failed requests.

Ethical Considerations

The Enhanced Web Crawler is designed with ethical considerations in mind:

  • Respect for Robots.txt: The tool automatically checks and adheres to robots.txt rules to ensure compliance with website policies.
  • Rate Limiting: Users can configure rate limits to avoid overloading servers with too many requests.
  • Proxy Rotation: Helps distribute requests across multiple IPs, reducing the risk of overwhelming a single server.
  • Transparency: Clear documentation ensures users understand how to use the tool responsibly.

Always ensure that you have permission to crawl a website and that your actions comply with applicable laws and terms of service.

Python, Web Crawler
Python Web Crawler
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