Selenium CSS selector for nth occurrence of td span:nth-child(2)

问题

The css selector td span:nth-child(2) means the 2nd child node span of td. I wanna choose the nth td span:nth-child(2), something like:

driver.find_element_by_css_selector("td span:nth-child(2):eq(4)")

I know I can use

driver.find_elements_by_css_selector("td span:nth-child(2)")[4]

or xpath instead:

driver.find_elements_by_xpath('(//td/span[2])[4]')

I just wanna know if I can do the same thing with css selector.

回答1:

You can't do this with a CSS selector. :eq() is from jQuery and not part of any standard.

td:nth-child(4) span:nth-child(2) means something entirely different, and will only work in very specific situations, such as when there is exactly one table row with four td elements all of which contain at least two span children:

<body>
  ...
  <table>
    <!-- The first, or only, row in the entire document
         with this many cells containing this many spans -->
    <tr>
      <td>
        <span></span>
        <span></span>
      <td>
        <span></span>
        <span></span>
      <td>
        <span></span>
        <span></span>
      <td>
        <span></span>
        <span></span>
  </table>
  ...
</body>

It won't match the element you're looking for in this example, because each tr has only two td children, so td:nth-child(4) will never match:

<body>
  ...
  <table>
    <tr>
      <td>
        <span></span>
        <span></span>
      <td>
        <span></span>
        <span></span>
    <tr>
      <td>
        <span></span>
        <span></span>
      <td>
        <span></span>
        <span></span> <!-- (//td/span[2])[4] -->
  </table>
  ...
</body>

If you know td:nth-child(4) span:nth-child(2) is guaranteed to work in your situation though, feel free to use it.

回答2:

If I am understanding your question correctly, you can use nth-child() on the td as well:

driver.find_elements_by_css_selector("td:nth-child(4) span:nth-child(2)")

来源：https://stackoverflow.com/questions/31778616/selenium-css-selector-for-nth-occurrence-of-td-spannth-child2

标签

python

selenium

xpath

css-selectors