为什么不能用硒获得 hkdrates 表？

Question

我想用 selenium 获取 hkdrates 表：

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

chrome_options = Options()
browser = webdriver.Chrome(options=chrome_options,executable_path='/usr/bin/chromedriver')
browser.get("https://www.bochk.com/en/investment/rates/hkdrates.html")

现在网页包含使用 selenium 的 chrome 驱动程序打开的 hkdrates：

xpath 是 //*[@id="form-div"]/form/div/table[1]，在 chrome 中显示。

browser.find_elements_by_xpath('//*[@id="form-div"]/form/div/table')
[]
browser.find_elements_by_xpath('.//table') 
[]

他们都一无所获，那么如何获得hkdrates表呢？

Answer 1

你的意思是它在 iframe 里面的表，你需要先切换。你可以使用一个方法：

.frame_to_be_available_and_switch_to_it

iframe 有一个id: iframe

对于您的hkdrates table，您可以使用css selector: .form_table.import-data.second-right

browser.get('https://www.bochk.com/en/investment/rates/hkdrates.html')

WebDriverWait(browser, 20).until(EC.frame_to_be_available_and_switch_to_it((By.ID, 'iframe')))
hkdrates_tbl = browser.find_element_by_css_selector('.form_table.import-data.second-right')
print(hkdrates_tbl.text)
browser.quit()

导入后：

from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

Answer 2

您的表格位于 iframe 内，请更改 https://www.bochk.com/whk/rates/exchangeRatesHKD/exchangeRatesHKD-input.action?lang=en 的网址

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

chrome_options = Options()
browser = webdriver.Chrome(options=chrome_options,executable_path='/usr/bin/chromedriver')
browser.get("https://www.bochk.com/whk/rates/exchangeRatesHKD/exchangeRatesHKD-input.action?lang=en")
table=browser.find_elements_by_xpath('//*[@id="form-div"]/form/div/table/tbody/tr')
for x in table:
    print(x.text)

Answer 3

要使用 Selenium 获取 hkdrates 表，因为所需元素位于 <iframe> 内，因此您必须：

• 为所需的frame_to_be_available_and_switch_to_it() 诱导 WebDriverWait。
• 为所需的visibility_of_all_elements_located() 诱导 WebDriverWait。

• 您可以使用以下解决方案：

  • 代码块：

    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
    
    options = webdriver.ChromeOptions()
    options.add_argument("start-maximized")
    driver = webdriver.Chrome(options=options, executable_path=r'C:\Utility\BrowserDrivers\chromedriver.exe')
    driver.get("https://www.bochk.com/en/investment/rates/hkdrates.html")
    WebDriverWait(driver, 20).until(EC.frame_to_be_available_and_switch_to_it((By.XPATH,"//iframe[@id='iframe' and starts-with(@src, '/whk/rates/exchangeRatesHKD/exchangeRatesHKD-input')]")))
    WebDriverWait(driver, 20).until(EC.visibility_of_all_elements_located((By.CSS_SELECTOR, "table.form_table.import-data.second-right tbody tr")))
    print(driver.find_element_by_css_selector("table.form_table.import-data.second-right tbody").text)
    

  • 控制台输出：

    Currency Buy Sell
    CNY 90.290000 89.360000
    CNH 90.380000 89.400000
    USD 782.250000 785.250000
    GBP 1,008.800000 1,020.400000
    JPY 721.000000 730.200000
    AUD 536.950000 543.800000
    NZD 500.200000 506.650000
    CAD 591.950000 599.100000
    EUR 868.400000 878.400000
    CHF 790.350000 797.850000
    DKK 116.150000 117.750000
    NOK 85.000000 86.400000
    SEK 80.650000 82.150000
    SGD 575.200000 579.450000
    THB 25.550000 26.550000
    BND 575.200000 579.450000
    ZAR 51.000000 52.950000
    

在这里你可以找到Ways to deal with #document under iframe的相关讨论