With the advent of the Internet era, capturing data on the Internet has become an increasingly important task. In the field of Web front-end development, we often need to obtain data from the page to complete a series of interactive operations. In order to improve efficiency, we can automate this work.
This article will introduce how to use PHP and Selenium for automated data collection and crawler crawling.
1. What is Selenium
Selenium is a free open source automated testing tool, mainly used for automated testing of web applications. It can simulate real user behavior and achieve automatic interaction. Use Selenium to automate browser operations such as clicking, typing, etc.
2. Install Selenium
Selenium is a library in the Python environment. We need to install Selenium first. The command is as follows:
pip install selenium
Next, you need to download the browser driver , taking Chrome as an example, the driver download address is: http://chromedriver.chromium.org/downloads. After downloading, extract it to a directory and add the directory to the system environment variable.
3. Use Selenium to obtain page data
After completing the installation of Selenium, you can use PHP to write a program to automatically obtain page data.
The following is a simple sample code. The program automatically opens the Chrome browser, accesses the target URL, waits for the page to load, obtains the target data, and outputs it to the console:
<?php require_once('vendor/autoload.php'); // 引入Selenium的PHP库 use FacebookWebDriverRemoteDesiredCapabilities; use FacebookWebDriverRemoteRemoteWebDriver; $host = 'http://localhost:9515'; // Chrome浏览器驱动程序地址 $capabilities = DesiredCapabilities::chrome(); $options = new FacebookWebDriverChromeChromeOptions(); $options->addArguments(['--headless']); // 启动无界面模式 $capabilities->setCapability(FacebookWebDriverChromeChromeOptions::CAPABILITY, $options); $driver = RemoteWebDriver::create($host, $capabilities); $driver->get('http://www.example.com'); // 要爬的页面地址 $driver->wait(5)->until( FacebookWebDriverWebDriverExpectedCondition::visibilityOfElementLocated( FacebookWebDriverWebDriverBy::tagName('h1') ) ); // 等待页面加载完成 $title = $driver->findElement(FacebookWebDriverWebDriverBy::tagName('h1'))->getText(); // 获取页面上的标题 echo $title; // 输出页面标题 $driver->quit(); // 退出浏览器驱动程序
In In the above sample code, the Chrome browser is used as the crawler tool, and the headless mode is started through the '--headless' parameter. After accessing the page, the program uses explicit waiting to wait for the page to be loaded and obtains the title data on the page.
4. How to deal with the anti-crawling mechanism?
When we want to crawl the data of a website through a crawler, we often encounter anti-crawling mechanisms, such as verification codes, User-Agent detection, etc. At this time, we can deal with it in the following ways:
Set the User-Agent to the browser's User-Agent, as common The User-Agents are:
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:57.0) Gecko/20100101 Firefox/57.0 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 Edge/16.16299
By using proxy IP, you can avoid the risk of being blocked by the website. Common proxy IP sources include overseas service providers , popular proxy IP pools, etc.
Use browser simulation tools, such as Selenium, to deal with the anti-crawling mechanism by simulating real user behavior.
5. Summary
Selenium is a powerful automated testing tool that can also be used as an effective tool in the crawler field. With PHP and Selenium, you can quickly write an efficient automated collection and crawler tool to achieve automated web page data acquisition.
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