How to get value of content attribute from span class

My diction is going to be wrong, so forgive the misnomers. I'm looking for the text of the "content" within the span class:

<span class="rating-label" content="5">

I'm looking for "5"

I've tried

driver.find_element_by_class_name('rating-label').text

But I do not receive the "5" back anywhere in that text.

I've also tried

driver.find_elements_by_class_name('rating-label').get_attribute("outerHTML")
driver.find_elements_by_class_name('rating-label').get_attribute("innerHTML")

I've checked the other questions about this, but if I missed one feel free to show me.

Thanks