NoSuchElementException:消息:无法定位元素://span[contains(text(),'Distance')]

我有这个代码,但它失败了,出现了错误 NoSuchElementException: Message: Unable to locate element: //span[contains(text(), 'Distance')] .

这是 page 我用来刮的。对于我的输入数据, distance 应等于:

261.30(海里)/300.76(英里)/483.93(公里)

我的代码有什么问题?我检查了所有元素的指定是否正确。

import time
from   selenium import webdriver
from   selenium.webdriver.support.ui import WebDriverWait
from   selenium.common.exceptions import NoSuchElementException
from   selenium.webdriver.firefox.options import Options

options = Options()
options.headless = True
browser = webdriver.Firefox(options=options)
browser.get("https://www.flightmanager.com/content/timedistanceform.aspx")

departure_airport = browser.find_element_by_id("ContentPlaceHolder1_txtDepartureICAO")
arrival_airport = browser.find_element_by_id("ContentPlaceHolder1_txtArrivalICAO")
submit   = browser.find_element_by_id("ContentPlaceHolder1_BtnSubmit")

departure_airport.send_keys("LEMD")
arrival_airport.send_keys("LEBL")

submit.click()

delay = 3 # seconds

try:
    WebDriverWait(browser, delay)
    distance = browser.find_element_by_xpath("//span[contains(text(), 'Distance')]").text
    print(distance)
    time.sleep(10)
except NoSuchElementException:
    print("Scraping failed")
    time.sleep(10)

browser.quit()