只有class怎么定位元素

定位不到元素怎么搞
wd.find_element(By.CLASS_NAME,"title f32 c_f").click()

下面是我的代码
from selenium import webdriver
from selenium.webdriver.common.by import By
import time

wd = webdriver.Chrome()
wd.get("https://www.xuetangx.com/course/Wuhanty04021002450/12425081?channel=i.area.learn_title%22)
wd.maximize_window()
wd.find_element(By.CLASS_NAME,"join f16 c_3").click()
time.sleep(1)

class 和下path都不能定位到

img


wd.find_element(By.CLASS_NAME,".join").click()
wd.find_element(By.CLASS_NAME,".f16").click()
wd.find_element(By.CLASS_NAME,".c_3").click()

这样试一下看看

wd.find_element(By.XPATH,"//*[@id="app"]/div/div[3]/div[1]/div[4]/div[2]/button").click()
试试

我用这个可以 不知道为什么
WebDriverWait(wd,2).until(expected_conditions.presence_of_element_located((By.XPATH,"/"))).click()