[Answer]-Storing a users submitted jQuery values in a Python/Django view

This should “work”:

        if step in (5, 6, 7):
            image = random.choice(PATH_ONE_IMAGES)   
            images.insert(step - 5, image)        
            PATH_ONE_IMAGES.remove(image)
            context['display_image'] = image 

            if step > 5:  
                slider_value = self.request.POST.get('slider_value')
                slider_DV_values.insert(step - 5, slider_value)                    

Or this:

        if step in (5, 6, 7):
            image = random.choice(PATH_ONE_IMAGES)   
            images.insert(step - 5, image)        
            PATH_ONE_IMAGES.remove(image)
            context['display_image'] = image 

            slider_value = self.request.POST.get('slider_value')
            if slider_value is not None:
                slider_DV_values.insert(step - 5, slider_value)