How to get the length of the <li> elements in an <ol> with Selenium in Python?

问题

I have an <ol> list in my HTML like the following:

<ol id="search-results">
  <li class="foo">-</li>
  <li class="foo">-</li>
  <li class="foo">-</li>
  <li class="foo">-</li>
</ol>

What I need to do is to verify that the <ol> list contains <li> items within, ie. a search query comes up with actual results. My current code is as follows:

search_field = driver.find_element(By.NAME, 'query')
search_field.send_keys('Foo')
search_field.submit()

results_list = driver.find_element(By.ID, 'search-results')
assert len(results_list) > 0

but I get the TypeError: object of type 'FirefoxWebElement' has no len() error when I run that.

Any ideas how to overcome that?

回答1:

Your

driver.find_element(By.ID, 'search-results')

don't return a list but an element. If you want the list with all the li, you could use the find_elements_by_xpath.

Try with:

results_list = driver.find_elements_by_xpath("//ol[@id='search-results']/li[@class='foo']")
print(len(results_list))
assert len(results_list) > 0

回答2:

Try the following:

search_field = driver.find_element(By.NAME, 'query')
search_field.send_keys('Foo')
search_field.submit()

results_list = driver.find_elements(By.CSS_SELECTOR, '#search-results > li')
assert len(results_list) > 0

来源：https://stackoverflow.com/questions/47038152/how-to-get-the-length-of-the-li-elements-in-an-ol-with-selenium-in-python