Python Portia Class Library Introduction Guide

Python Portia Class Library Introduction Guide Portia is a powerful Python class library for automated crawling and extracting web data.It is based on the SCRAPY framework and can help developers quickly build cyber crawlers, including dynamic web pages that require JavaScript support.This article will introduce the basic concepts, installation processes and usage methods of Portia. First, we need to install the Portia class library.You can use the PIP package manager to run the following commands to install Portia: pip install portia After the installation is completed, we can use the Portia command line tool to create a new project.Run the following command: portiacrawl my_project This will create a new project called `my_project`.Enter the project directory: cd my_project Now we can use Portia's web interface to define our crawling rules.Run the following command to start the web interface: portia Then visit the `http:// localhost: 9001`. In the web interface, we can create a new crawler to define data extraction rules.First, click the "New Spider" button and then provide a name for the crawler. Next, we need to start the Portia's proxy server.Click the "Proxy" button in the navigation bar above, and then click "Start" to start the agent. Now, we can start defining crawling rules.Use the "ADD A PAGE" button in the web interface to add a web page to be crawled.In the open editing page, enter the URL of the webpage to crawl and click "Capture" to capture the content of the page. After the page content capture is completed, we can use the selector to extract interesting data.Click the elements in the web preview, and then click the "Extract Data" button to select the position and method of data extraction.We can use XPath, CSS selectors or regular expressions to define data extraction rules. After completing the definition of data extraction rules, you can click "Save Changes" to save reptile configuration. Next, we can use Portia's command line tool to run crawlers.Back to the command line interface, run the following command: portiacrawl run spider_name Replace the `Spider_name` to the reptile name we created before. Portia will start climbing the target webpage and extract data from interesting according to the rules we define. The above is the basic process of creating and running network crawlers using the Python Portia class library.In addition, Portia also provides many advanced functions and configuration options, which can be expanded and optimized according to specific needs. To sum up, Portia is a powerful Python library that helps developers to quickly build efficient network crawlers.By using its web interface, we can easily define crawling rules and data extraction rules without writing complex code.Both beginners or experienced developers can easily implement Web data crawling and extraction tasks through Portia.