driver.find_element_by_class_name() but the class name has spaces

Question

Error message : selenium.common.exceptions.InvalidSelectorException: Message: Given css selector expression ". clickable event-link math " is invalid: InvalidSelectorError: Document.querySelector: '. clickable event-link math ' is not a valid selector: ". clickable event-link math "

My guess is due to the spaces cause I saw similar issues with spaces but couldn't find a solution that worked for me

Algebra = ' clickable event-link math '
math = driver.find_element_by_class_name(Algebra)

Answer 1

As per the documentation of selenium.webdriver.common.by implementation:

class selenium.webdriver.common.by.By
    Set of supported locator strategies.

    CLASS_NAME = 'class name'
    

So,

• Using find_element_by_class_name() you won't be able to pass multiple class names. Passing multiple classes you will face the error as:

    Message: invalid selector: Compound class names not permitted
  

• Additionally, as you want to return an array of the chats, so instead of find_element* you need to use find_elements*

---

Solution

As an alternative you can use either of :the following Locator Strategies:

• CSS_SELECTOR:

    math = driver.find_element(By.CSS_SELECTOR, ".clickable.event-link math")
  

• XPATH:

    math = driver.find_element(By.XPATH, "//*[contains(@class, 'clickable') and contains(@class, 'event-link math')]")
  

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References

You can find a couple of relevant detailed discussions in:

• Invalid selector: Compound class names not permitted error using Selenium
• How to locate an element with multiple class names?

Answer 2

It means that element has several classes... Try to use CSS-selector

driver.find_element_by_css_selector(".clickable.event-link.math")