Python遍历文件夹下指定文件

import os
def searchWithName(dir,filename,slist=[]):
    for lists in os.listdir(dir):
        path = os.path.join(dir,lists)
        if os.path.isfile(path):
                dirc,fileNm = os.path.split(path)
                if fileNm == filename:
                    slist.append(dirc+"\\"+fileNm)
        if os.path.isdir(path):
            searchWithName(path,filename,slist)
        return slist