正则表达式结尾处没有数字和字符串的开头

I've been searching for a Regex to match a string that has no digit at the end and the beginning. Since this is a password complexity requirement I have to implement, I thought that there would be at least one example for this use case, but I couldn't find anything like that. Also my own attempts were not successful to create such a Regex.I've been searching for a Regex to match a stri