def render_groups self group result def do_render_group for in group S

def render_groups(self):
    group = []
    result = []
    
    def do_render_group():
        for j in group:
            # Some fancy logic here
            result.append(j)
                
    prev_value = None
            
    for obj in self._data:
        if (obj.value != prev_value):
            do_render_group()
            group = []
        
        group.append(obj)
        prev_value = obj.prev_value
        
    if (len(group) > 0):
        do_render_group()

    return result