Lookup ERROR while trying to click on multiple visible elements on the page Helium/Selenium

Question

I'd appreciate any help on this issue.

I'm trying to click (to expand) all years and months elements on this page:

<tbody ng-repeat="year">
   <tr class="year expandable title">
      <th><a>2020</a></th>
   </tr>
   <tr class="month expandable title ng-hide">
      <th><a><span class="display">December 2020</span></a></th>
   </tr>
    <!-- [...] ALL OTHER MONTHS, SAME STRUCTURE -->
</tbody>
<tbody ng-repeat="year">
   <tr class="year expandable title">
      <th><a>2019</a></th>
   </tr>
   <tr class="month expandable title ng-hide">
      <th><a><span class="display">December 2019</span></a></th>
   </tr>
    <!-- [...] ALL OTHER MONTHS, SAME STRUCTURE -->
</tbody>

When trying this code below I always get a Lookup error.

for y in find_all(S('.year.expandable')):
  click(y)

for m in find_all(S('.month.expandable')):
  click(m)

Here's the traceback:

Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
  File "/usr/local/lib/python3.9/site-packages/helium/__init__.py", line 273, in click
    _get_api_impl().click_impl(element)
  File "/usr/local/lib/python3.9/site-packages/helium/_impl/__init__.py", line 202, in click_impl
    self._perform_mouse_action(element, self._click)
  File "/usr/local/lib/python3.9/site-packages/helium/_impl/__init__.py", line 37, in f_decorated
    result = f(self, *args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/helium/_impl/__init__.py", line 56, in f_decorated
    return f(*args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/helium/_impl/__init__.py", line 240, in _perform_mouse_action
    self._manipulate(element, lambda wew: action(wew.unwrap(), offset))
  File "/usr/local/lib/python3.9/site-packages/helium/_impl/__init__.py", line 301, in _manipulate
    driver.last_manipulated_element = gui_or_web_elt.perform(action)
  File "/usr/local/lib/python3.9/site-packages/helium/_impl/__init__.py", line 648, in perform
    raise LookupError()
LookupError

Not sure why but it works If I click on just one element click(S('.year.expandable'))

Any idea what could be wrong?

Answer 1

The DOM appear to be changing upon interaction hence the error. I found a workaround without using Helium. I wrote a custom function that uses driver.find_elements_by_xpath(xpath) to spot and click the DOM elements using selenium.

    driver = helium.get_driver()
    for h in range(len(driver.find_elements_by_xpath(xpath))):
        try:
            sleep(random.uniform(1,1.25)) #otherwise misclicks
            highlight(S(xpath))     #to avoid StaleElement Exceptions
            S(xpath).web_element.click()
        except Exception as e:
            print(e)
            continue

The code does the trick. Not entirely sure why but I had to add highlight(S(xpath)) to make sure to have the click go through, otherwise the code randomly returnes a StaleElement Exception.

I know it's hacky but if anyone else has a better solution please feel free to comment.