python 参数值等于None怎么用

def test(query, m=None):
    """
    m: string
    """
    # 看了下，一般都这样写：如果is None时候初始化下
    if m is None:
        m = ""
    return query + m

if __name__ == "__main__":
    # 既支持这样
    query = "辛弃疾"
    print(test(query))
    
    # 也支持这样
    query = "辛弃疾"
    m = "诗人"
    print(test(query, m))