python webdriver：find_element（）找不到元素
通过以下内容，我正在学习Web刮擦的基础知识，其中包括使用Python自动化无聊的东西的第12章，但是我对Find_element（）方法有一个问题。当我使用该方法查找具有“ card-img-top cover-thumb”类名称的元素时，该方法不会返回任何匹配项。但是，代码确实适用于本书中的示例。
为了使代码做任何事情，我不得不对代码进行了很多更改。我已经在github上发布了完整的代码
这本书说要使用'find_element_by_*'方法，但是这些方法正在产生指示我使用find_element（）的折旧消息。
要使用这种其他方法，我会导入'。
我也从'selenium.webdriver.chrome.service'导入“服务”，因为Chromedriver否则不起作用。
我还使用webdriver.chromeoptions（）定义选项，隐藏了有关故障设备的某些错误消息，显然您应该忽略？
我将书中的代码放入具有“ url”和“ className”参数的函数中，以便我可以测试不同的URL，而无需重复编辑代码。
这是代码的“业务零件”：
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.by import By
s=Service(r'C:\Users\antse\AppData\Local\Chrome_WebDriver\chromedriver.exe')
op = webdriver.ChromeOptions()
op.add_experimental_option('excludeSwitches', ['enable-logging'])
def FNC_GET_CLASS_ELEMENT_FROM_PAGE(URL, CLASSNAME):
browser = webdriver.Chrome(service = s, options = op)
browser.get(URL)
try:
elem = browser.find_element(By.CLASS_NAME, CLASSNAME)
print('Found <%s> element with that class name!' % (elem.tag_name))
except:
print('Was not able to find an element with that name.')
FNC_GET_CLASS_ELEMENT_FROM_PAGE('https://inventwithpython.com', 'card-img-top cover-thumb')
预期输出：找到＆lt; img＆gt;该班级名称的元素！
由于当我查看像Wikipedia这样的网站时，该代码确实可以工作，所以我想知道该页面的HTML是否有更改可以防止刮擦正常工作？
链接到书章在这里。
感谢您可以给我任何建议！
I'm learning the very basics of Web Scraping by following Chapter 12 of Automate the boring stuff with Python, but I'm having an issue with the find_element() method. When I use the method to look for an element with the class name 'card-img-top cover-thumb', the method doesn't return any matches. However, the code does work for URL's other than the example in the book.
I have had to make quite a few changes to the code as-written in order to get the code to do anything. I've posted the full code on GitHub HERE, but to summarise:
The book says to use 'find_element_by_*' methods, but these were producing depreciation messages that directed me to use find_element() instead.
To use this other method, I import 'By'.
I also import 'Service' from 'Selenium.Webdriver.Chrome.Service' because Chromedriver doesn't work otherwise.
I also define options with Webdriver.ChromeOptions() that hide certain error messages about a faulty device which apparently you're just supposed to ignore?
I put the code from the book into a function with 'url' and 'classname' arguments so I can test different url's without having to edit the code repeatedly.
Here is the 'business-part' of the code:
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.by import By
s=Service(r'C:\Users\antse\AppData\Local\Chrome_WebDriver\chromedriver.exe')
op = webdriver.ChromeOptions()
op.add_experimental_option('excludeSwitches', ['enable-logging'])
def FNC_GET_CLASS_ELEMENT_FROM_PAGE(URL, CLASSNAME):
browser = webdriver.Chrome(service = s, options = op)
browser.get(URL)
try:
elem = browser.find_element(By.CLASS_NAME, CLASSNAME)
print('Found <%s> element with that class name!' % (elem.tag_name))
except:
print('Was not able to find an element with that name.')
FNC_GET_CLASS_ELEMENT_FROM_PAGE('https://inventwithpython.com', 'card-img-top cover-thumb')
Expected output: Found <img> element with that class name!
Since the code does work when I look at a site like Wikipedia, I wonder if there have been changes to the html of the page that prevents the scrape from working properly?
Link to the book chapter HERE.
I appreciate any advice you can give me!
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您不能将多个类传递给
find_element。只有一个可以在场。因此，请替换以下内容：
如果您真的想使用这两个类详细。
You can't pass multiple classes to
find_element. Only one can be present. So replace this:with this:
If you really want to use both classes, then take a look at this answer which explains things in detail.