Selenium webdriver 检索一个空列表

Question

我有这段代码：

from selenium import webdriver
from selenium.webdriver.firefox.options import Options as FirefoxOptions
firefox_options = FirefoxOptions()
firefox_options.add_argument("--headless")
driver = webdriver.Firefox(executable_path = "../../bin/geckodriver", options = firefox_options)

driver.get('https://www.go2roues.com/shop/?category=7&puissance=null&brands=&batterieAmovible=false&connecte=false&livraison=false&capacite=false')

elems = driver.find_elements_by_class_name("pf_pg__product")

print(elems)

从脚本执行此代码时，我得到一个空列表：

[]

当使用相同的 python 二进制文件执行相同的代码时，我的 Python 解释器会得到一个非空的对象列表：

[, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ]

我不知道问题出在哪里。感谢您的帮助

Answer 1

您在获取元素列表之前错过了延迟。
在访问所需的 Web 元素之前，应完全加载它们。
让您的代码正常工作的最简单方法是添加一些延迟：

from selenium import webdriver
from selenium.webdriver.firefox.options import Options as FirefoxOptions
firefox_options = FirefoxOptions()
firefox_options.add_argument("--headless")
driver = webdriver.Firefox(executable_path = "../../bin/geckodriver", options = firefox_options)

driver.get('https://www.go2roues.com/shop/?category=7&puissance=null&brands=&batterieAmovible=false&connecte=false&livraison=false&capacite=false')

time.sleep(10)
elems = driver.find_elements_by_class_name("pf_pg__product")

print(elems)

为了让它更好，你应该使用如下的显式等待：

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.firefox.options import Options as FirefoxOptions
firefox_options = FirefoxOptions()
firefox_options.add_argument("--headless")
driver = webdriver.Firefox(executable_path = "../../bin/geckodriver", options = firefox_options)

wait = WebDriverWait(driver, 20)
driver.get('https://www.go2roues.com/shop/?category=7&puissance=null&brands=&batterieAmovible=false&connecte=false&livraison=false&capacite=false')

#wait for the foirst element matching the passed locator presence
wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, ".pf_pg__product")))

#add a short delay to make all the elements loaded
time.sleep(0.6)

#get the elements list
elems = driver.find_elements_by_class_name("pf_pg__product")

print(elems)