pat = r'!\[\]'
pat = r"[a-zA-Z0-9_\u4e00-\u9fa5\.() ]{1,}\.(?:png|jpg|gif)" # 比如st = "关于哈哈的需求v2. (2)1_html_fjf3hg4bv5h.jpg" # 匹配到了['关于哈哈的需求v2. (2)1_html_fjf3hg4bv5h.jpg']