python通过key来比较

class Solution:
    

    def reorderLogFiles(self, logs: List[str]) -> List[str]:
        def cmp(x: string) -> list:
            i = x.find(' ');
            x1 = x[0:i] #标识符
            x2 = x[i+1:] #日志

            return [x2,x1]


        a = [] #字母
        b = [] #数字
        for log in logs:
            i = log.find(' ')
            if '0' <= log[i+1] <= '9':
                b.append(log)
            else:
                a.append(log)
        
        a.sort(key=cmp)

        return a+b