Since everything in python is an object even the python module has some useful properties. One of them is __dict__ property. This is how you can use it.
className = 'MyClass' modObj = __import__('moduleName') # This gives us the class reference MyClass = modObj.__dict__[className] # So we can create class instance like this inst = MyClass(params)
This logic works if you are using just modules. For packaging this may need to be modified.