你匹配年份的顺序是:

([19s[2-9s][0-9s])dd

看起来格式不正确，因为括号不匹配.

Which looks malformed, as the brackets do not match.

另外，两个数字的存在(使用d)意味着表达式将不匹配空格.

Also, the presence of the two digits (using d) means that the expression will not match white space.