无法通过Chrome使用Selenium获取元素文本

Question

我正在尝试使用Python和Chrome作为Selenium webdriver来抓取Merriam-Webster's Medical Dictionary中的医学术语。到目前为止，我得到的是：

    from os import path
    from selenium import webdriver

    # Adding an ad-blocker to Chrome to speed up page load times
    options = webdriver.ChromeOptions()
    options.add_extension(path.abspath("ublock-origin.crx"))

    # Declaring the Selenium webdriver
    driver = webdriver.Chrome(chrome_options = options)

    # Fetching the "A" terms as a test set
    driver.get("https://www.merriam-webster.com/browse/medical/a")

    scraped_words = []  # The list that will hold each word
    page_num = 1
    while page_num < 55:  # There are 54 pages of "A" terms
        try:
            for i in range(4):  # There are 3 columns per page of words
                column = "/html/body/div/div/div[5]/div[2]/div[1]/div/div[3]/ul/li[" + str(i) + "]/a"
                number_of_words = len(driver.find_elements_by_xpath(column))
                for j in range(number_of_words):
                    word = driver.find_elements_by_xpath(column + "[" + str(j) + "]")
                    scraped_words.append(word)
            driver.find_element_by_class_name("fa-angle-right").click()  # Next page
            page_num += 1  # Increment page number to keep track of current page
        except:
            driver.close()

    # Write out words to a file
    with open("medical_terms.dict", "w") as text_file:
        for i in range(len(scraped_words)):
            text_file.write(str(scraped_words[i]))
            text_file.write("\n")

    driver.close()

上面的代码获取所有项，因为len(scraped_words)的输出是预期的数字。但是，因为我没有指定要获取元素的文本，所以我得到了元素标识符(我想？)而不是文本。如果我决定使用word = driver.find_elements_by_xpath(column + "[" + str(j) + "]").text来指定我想要获取元素的文本，我会得到以下错误：

Traceback (most recent call last):
  File "mw_download.py", line 20, in <module>
    number_of_words = len(driver.find_elements_by_xpath(column))
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 325, in find_elements_by_xpath
    return self.find_elements(by=By.XPATH, value=xpath)
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 817, in find_elements
    'value': value})['value']
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 256, in execute
    self.error_handler.check_response(response)
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: no such session
  (Driver info: chromedriver=2.31.488774 (7e15618d1bf16df8bf0ecf2914ed1964a387ba0b),platform=Mac OS X 10.12.6 x86_64)


During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "mw_download.py", line 27, in <module>
    driver.close()
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 541, in close
    self.execute(Command.CLOSE)
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 256, in execute
    self.error_handler.check_response(response)
  File "/usr/local/lib/python3.6/site-packages/selenium/webdriver/remote/errorhandler.py", line 194, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: no such session
  (Driver info: chromedriver=2.31.488774 (7e15618d1bf16df8bf0ecf2914ed1964a387ba0b),platform=Mac OS X 10.12.6 x86_64)

这里让我感到奇怪的是，我在两次运行之间唯一更改的代码是在第22行，但错误消息却指向第20行。

如果能帮助我破译这里发生的事情，以及我能做些什么来修复它，我们将不胜感激！:+)

Answer 1

你只需要创建一个words列表来访问你的元素文本，改变：

word = driver.find_elements_by_xpath(column + "[" + str(j) + "]")

至：

word = [i.text for i in driver.find_elements_by_xpath(column + "[" + str(j) + "]")]

因为.find_elements_by_xpath总是返回一个列表，所以直接访问.text是行不通的。