def natural_sort_key(layer_name):
    """自然排序键函数，将字符串中的数字部分转换为整数进行排序"""
    import re
    def convert(text):
        return int(text) if text.isdigit() else text.lower()

    return [convert(c) for c in re.split('([0-9]+)', layer_name)]

s = natural_sort_key("DSA_2_1_2")
c = lambda x: natural_sort_key(x.layer_name)
print(s)