XPath

Advice

Use Chrome's dev tools to test your XPath selectors quickly!

Here's a particularly tricky selector:

haha_element = add_reaction_button.find_element_by_xpath('//span[@aria-label="Haha" and '
                                                         'ancestor::div[@aria-label="Reactions"] and '
                                                         'not(ancestor::div[contains(@class,"fb_content")])]')