python 2.7 - Unique content identifier with Selenium: InvalidSelectorError -

i'm trying grab data from: http://www.boerse-frankfurt.de/de/etfs/ishares+msci+world+momentum+factor+ucits+etf+de000a12bhf2

the types of data i'm looking located in classes named singlebox list_component. let's want extract total expense ratio (0.30%). located in td class called: right column-datavalue lastcolofrow.

but if do:

dues = driver.find_element_by_class_name("right column-datavalue lastcolofrow ") expense_ratio = re.search(r"(.{4})(?=%)", dues.text).group(0).encode("utf-8") 

i get:

invalidselectorerror: compound class names not permitted 

and adding problem, there seem multiple instances of right column-datavalue lastcolofrow doesn't serve unique identifier.

note: if problem better solved beautifulsoup instead of selenium, please let me know.

you can use find_element_by_css_selector() instead match element multiple css classes :

dues = driver.find_element_by_css_selector(".right.column-datavalue.lastcolofrow") 

but claimed above selector isn't unique, can use xpath match css classes considering order (i found xpath unique on web page) :

xpath = "//td[@class='right column-datavalue lastcolofrow']" dues = driver.find_element_by_xpath(xpath) 

another way approach using xpath selecting <td> element follows <td> containing text gesamtkostenquote :

xpath = "//td[@class='column-datacaption' , normalize-space(text())='gesamtkostenquote']/following-sibling::td" dues = driver.find_element_by_xpath(xpath)