How to extract all href from a class in Python Selenium?

问题

I am trying to extract people's href from the URL https://www.dx3canada.com/agenda/speakers.

I tried:

elems = driver.find_elements_by_css_selector('.display-flex card vancouver')
href_output = []
for ele in elems:
    href_output.append(ele.get_attribute("href"))
print(href_output)

But the output list returns nothing...

The expected href shown as the image below and I hope the outputs as a list of hrefs:

I really appreciate the help!

回答1:

To extract the people's href attribute from the URL https://www.dx3canada.com/agenda/speakers as the the desired elements are within an <iframe> so you have to:

• Induce WebDriverWait for the desired frame to be available and switch to it.
• Induce WebDriverWait for the visibility of all elements located.

• You can use the following Locator Strategies:

  from selenium import webdriver
  from selenium.webdriver.support.ui import WebDriverWait
  from selenium.webdriver.common.by import By
  from selenium.webdriver.support import expected_conditions as EC
  
  options = webdriver.ChromeOptions() 
  options.add_argument("start-maximized")
  options.add_experimental_option("excludeSwitches", ["enable-automation"])
  options.add_experimental_option('useAutomationExtension', False)
  driver = webdriver.Chrome(options=options, executable_path=r'C:\WebDrivers\chromedriver.exe')
  driver.get('https://www.dx3canada.com/agenda/speakers')
  WebDriverWait(driver, 30).until(EC.frame_to_be_available_and_switch_to_it((By.CSS_SELECTOR,"iframe#whovaIframeSpeaker")))
  print([my_elem.get_attribute("href") for my_elem in WebDriverWait(driver, 30).until(EC.visibility_of_all_elements_located((By.CSS_SELECTOR, "a.display-flex.card.vancouver")))])
  

• Console Output:

  ['https://whova.com/embedded/speaker_detail/dcrma_202003/9942778/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907682/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907688/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907676/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907696/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907690/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907670/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907693/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9942779/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9908087/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907671/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907681/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907673/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907678/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907689/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907674/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907684/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907685/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907686/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9942780/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907695/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907687/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907683/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907692/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907672/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907697/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907680/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907679/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907675/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907677/', 'https://whova.com/embedded/speaker_detail/dcrma_202003/9907694/']
  

Here you can find a relevant discussion on Ways to deal with #document under iframe

回答2:

Your images are in an iframe, so you will need to switch to this before you can scrape the href attributes using frame_to_be_available_and_switch_to_it.

Then, to get the list of all href attributes, you may need to run some Javascript to scroll the image into view, and handle the case where the images may be lazy loading the href:

# first, switch to iframe
WebDriverWait(driver, 30).until(EC.frame_to_be_available_and_switch_to_it((By.XPATH,"//iframe[@id='whovaIframeSpeaker']")))

elements_list = driver.find_elements_by_xpath("//div[contains(@class, 'template-section-body')]/a[contains(@class, 'display-flex card vancouver')]")

for element in elements_list:
    driver.execute_script("arguments[0].scrollIntoView(true);", element)
    print(element.get_attribute("href"))

The results of this code:

回答3:

For your css selector use .display-flex.card.vancouver instead.

elems = driver.find_elements_by_css_selector('.display-flex.card.vancouver')

Each word is a class, so you need to place a dot in the front of each one.

来源：https://stackoverflow.com/questions/59145944/how-to-extract-all-href-from-a-class-in-python-selenium