def get_insts(class_name):
    """get_insts(class_name) -> instance_list"""
    ins_list = []
    import gc
    for obj in gc.get_objects():
        try:
            if getattr(obj, '__class__', None):
                if obj.__class__.__name__ == class_name:
                    ins_list.append(obj)
        except ReferenceError:
            continue
    return ins_list
