Question

我正在尝试使用Python和Chrome作为Selenium webdriver来搜索Merriam-Webster的医学词典。到目前为止，这就是我所拥有的：

    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()

上面的代码提取了所有项目，因为len(scraped_words)的输出是预期的数字。但是，由于我没有指定我想获取元素的文本，因此我得到元素标识符（我认为？）而不是文本。如果我决定使用word = driver.find_elements_by_xpath(column + "[" + str(j) + "]").text来指定我想获取元素的文本，我会收到以下错误：

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)

我在这里感到奇怪的是，我在运行之间更改的唯一代码是在第22行，但错误消息指出了第20行。

任何帮助解读这里发生的事情以及我可以做些什么来修复它都会非常感激！：+）

Answer 1

您只需创建一个访问元素文本的array_unshift($original,'dummy'); array_shift($original);列表，即可更改：

words

为：

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

由于word = [i.text for i in driver.find_elements_by_xpath(column + "[" + str(j) + "]")]将始终返回列表，因此直接访问.find_elements_by_xpath无法正常工作。

无法使用Selenium和Chrome获取元素文本

1 个答案: