网络抓取时如何绕过动态元素？

Question

The code below works as I am able to click a button on the webpage using Python/Selenium/Firefox.

button on the webpage

driver.execute_script('''return document.querySelector('dba-app').shadowRoot.getElementById('configRenderer').shadowRoot.querySelector('ing-default-layout-14579').querySelector('dba-overview').shadowRoot.querySelector('ing-feat-agreement-overview').shadowRoot.querySelector('ing-ow-overflow-menu-14587').shadowRoot.querySelector('button')''').click()

However, some elements are dynamic and the numbers are changing anytime you rerun the script.

The changing elements:

• 'ing-default-layout- 14579 '
• 'ing-ow-overflow-menu- 14587 '

What must I do to get around the dynamic elements?

Answer 1

One option is to look for other attributes that stay the same across pageloads. For example, given your HTML, you could do:

document.querySelector('#configRenderer') // returns the config renderer element
document.querySelector('[data-tag-name="ing-default-layout"]') // returns the ing-default-layout element
document.querySelector('[data-tag-name="dba-overview]') // returns the dba-overview element

And so on. Or you could the same method to identify a parent or a child, and then navigate to the child or parent respectively.

If the HTML isn't stable enough even for that, another approach would be to search through all elements, and find the one(s) whose tagName starts with what you need.

for (const elm of document.querySelectorAll('*')) {
  if (elm.tagName.toLowerCase().startsWith('ing-ow-overflow-menu')) {
    // do stuff with elm, which is the overflow menu element
  }
}