Selenium 4 Python如何等待元素属性值并处理进度条？

针对你遇到的Selenium 4中attributeToBe()方法被弃用的问题，以下是两种可行的解决方案，以demoqa的进度条页面为例：

方法一：使用显式等待+Lambda表达式（推荐） #

Selenium 4中ExpectedConditions.attributeToBe()已被标记为过时，可通过Lambda表达式自定义等待条件，实现等待进度条属性达到目标值后停止：

Java 示例 #

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.support.ui.WebDriverWait;
import java.time.Duration;

public class ProgressBarHandler {
    public static void main(String[] args) {
        WebDriver driver = new ChromeDriver();
        driver.get("https://demoqa.com/progress-bar");
        
        // 启动进度条
        WebElement startStopBtn = driver.findElement(By.id("startStopButton"));
        startStopBtn.click();
        
        // 定位进度条元素
        WebElement progressBar = driver.findElement(By.className("progress-bar"));
        
        // 等待进度条aria-valuenow属性等于"70"
        new WebDriverWait(driver, Duration.ofSeconds(10))
                .until(driverInstance -> progressBar.getAttribute("aria-valuenow").equals("70"));
        
        // 停止进度条
        startStopBtn.click();
        
        driver.quit();
    }
}

Python 示例 #

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait

driver = webdriver.Chrome()
driver.get("https://demoqa.com/progress-bar")

start_stop_btn = driver.find_element(By.ID, "startStopButton")
start_stop_btn.click()

progress_bar = driver.find_element(By.CLASS_NAME, "progress-bar")
# 等待进度条属性值达到70
WebDriverWait(driver, 10).until(
    lambda d: progress_bar.get_attribute("aria-valuenow") == "70"
)

start_stop_btn.click()
driver.quit()

方法二：使用循环检查属性值 #

如果更倾向于直观的逻辑，可通过循环持续检查进度条的属性值，达到目标后执行停止操作：

Java 示例 #

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;

public class ProgressBarLoop {
    public static void main(String[] args) throws InterruptedException {
        WebDriver driver = new ChromeDriver();
        driver.get("https://demoqa.com/progress-bar");
        
        WebElement startStopBtn = driver.findElement(By.id("startStopButton"));
        WebElement progressBar = driver.findElement(By.className("progress-bar"));
        
        startStopBtn.click();
        
        // 循环检查进度，直到达到70%
        while (true) {
            String currentProgress = progressBar.getAttribute("aria-valuenow");
            if ("70".equals(currentProgress)) {
                startStopBtn.click();
                break;
            }
            // 短暂休眠避免频繁占用资源
            Thread.sleep(50);
        }
        
        driver.quit();
    }
}

Python 示例 #

from selenium import webdriver
from selenium.webdriver.common.by import By
import time

driver = webdriver.Chrome()
driver.get("https://demoqa.com/progress-bar")

start_stop_btn = driver.find_element(By.ID, "startStopButton")
progress_bar = driver.find_element(By.CLASS_NAME, "progress-bar")

start_stop_btn.click()

while True:
    current_progress = progress_bar.get_attribute("aria-valuenow")
    if current_progress == "70":
        start_stop_btn.click()
        break
    time.sleep(0.05)

driver.quit()

两种方法均能实现需求：显式等待是Selenium官方推荐的方式，无需手动处理休眠逻辑；循环方式则更直观，适合简单场景。

内容的提问来源于stack exchange，提问作者Tanvir Ahmed