Issue with Selenium - Pop Up window

Question

有时有弹出窗口但有时不出现时如何放置条件。

Answer 1

    try{  
        WebDriverWait wait = new WebDriverWait(driver, 5);
        wait.until(ExpectedConditions.alertIsPresent());
        System.out.println(driver.switchTo().alert().getText());
        driver.switchTo().alert();  
    }     
    catch (NoAlertPresentException Ex)  
    {
        System.out.println("No alert");
    }

Answer 2

try the following

from selenium import webdriver
from selenium.common.exceptions import NoAlertPresentException


def example():
    firefox_browser = webdriver.Firefox(executable_path=r'geckodriver.exe')
    firefox_browser.get('https://www.google.com')

    """check if alert is displayed
    """
    try:
        alert = firefox_browser.switch_to.alert
    except NoAlertPresentException:
        print("No alert")
        return False
    else:
        return True


if __name__ == "__main__":
    example()