How to check if an element has a class in Selenium (Javascript, Python, Nightwatch)

Nightwatch

 // To check if an element has a class
 // Check the return value via the callback: true or false 
var hasClass = function(browser, element, theClass, f_callback) {
   var retVal = false;
   browser.getAttribute(element, 'class', function(res) {
     if (res.status === 0) { // ok 
       let classes = res.value.split(" ");
       if (classes.indexOf(theClass) >= 0) {
         retVal = true;
       }
     } else {
       console.log("ERROR: Failed to get attributes of element", element);
     }
     f_callback(retVal);
   });
 };

Python + Selenium

hasErrorClass = 'error' in divBlock.get_attribute('class').split(' ')