You don't extract from innerHTML
. Rather you extract text or the value of any attribute of a WebElement.
To extract the text _4.3 out of 5 stars_
you need to move one step deeper to the <span>
and you can use the following Locator Strategy:
ProductNames[3].find_element_by_css_selector('.aok-align-bottom>span.a-icon-alt').get_attribute("innerHTML")
Or simply:
ProductNames[3].find_element_by_css_selector('.aok-align-bottom>span').get_attribute("innerHTML")
As an alternative, you can also use the text attribute as follows:
ProductNames[3].find_element_by_css_selector('.aok-align-bottom>span.a-icon-alt').text
Or simply:
ProductNames[3].find_element_by_css_selector('.aok-align-bottom>span').text
References
You can find a couple of relevant discussions in: