Example tutorial of using the Portia class library to realize the Python network crawler

Example tutorial of using the Portia class library to realize the Python network crawler Introduction: Python is a powerful programming language with the ability to write network crawlers.Network crawlers are a kind of automation program that can extract data and process it from the webpage.Portia is a visual network crawler tool based on the SCRAPY framework, which provides a simple and efficient way to create and manage crawlers.This article will take you to understand how to use the Portia class library to implement the instance tutorial of Python network crawler. 1. Preparation: Before the beginning, we need to ensure that the Python and Scrapy frameworks have been installed.You can check whether the following command has been installed: python --version scrapy --version 2. Install Portia: After confirming that the Python and SCRAPY frameworks have been properly installed, we can use the following commands to install Portia: pip install slybot 3. Create project: Enter your working directory in the command line and run the following commands to create a SCRAPY project: scrapy startproject myproject 4. Run Portia: In the project directory, run the following commands to start Portia: slyd -p 9001 5. Create crawlers: Open the http:// localhost: 9001 in the browser and enter the Portia interface.Click the "New Spider" button to create a new crawler. 6. Add seed URL: On the reptile settings page, click the "ADD URL" button to add a seed URL.This will be the webpage you will capture. 7. Define Item: On the same settings page, click the "Add Field" button to define the data fields to be extracted from the webpage.You can add multiple fields according to your needs. 8. Tag data: In the page browser, use the mouse to drag the selection area according to the data to be extracted, and allocate labels for each field.This way, Portia can understand where to extract data. 9. Training reptile: After completing the mark, click the "Train Spider" button to train reptiles.This will help Portia learn how to extract data. 10. Test crawlers: After the training is completed, click the "Test Spider" button for testing.Check whether the reptile can be extract the data correctly and modify the part that needs to be adjusted. 11. Run reptile: On the Portia homepage, click the "deploy" button to deploy the reptile to the Scrapy project. 12. Write the crawler code: Enter the Spiders directory entering the SCRAPY project, and create a Python file in this directory, such as Spider.py.In this file, write the Python code to use the reptile generated by Portia. 13. Configuration reptile: In the Spider.py file, the necessary scrapy configuration is added, such as setting the capture delay, specified input and output format. 14. Run reptile: In the command line, enter the SCRAPY project directory, and use the following command to start the reptile: scrapy crawl spider_name The Spider_name here is the name of the reptiles you created in Portia. 15. View results: After the crawler runs, the extracted data will be processed according to your configuration in the Spider.py file.You can specify saving data to files, databases, etc. Summarize: This article uses the instance tutorials of Python network crawlery using the Portia class library, and introduces the steps of using Portia to create reptiles, training reptiles, testing reptiles, and composing crawlers.Through such a tutorial, you will be able to quickly use Portia to build a network crawler for specific websites and extract data interested.Happy Crawling!