python 枚举目录下所有子目录和文件，输出列表

#WalkDir函数枚举目录中所有目录和文件，参数（枚举目录输出列表，枚举文件输出列表，要枚举的目录）
def WalkDir(dirlist,filelist,dirname):
    try:
        ls=os.listdir(dirname)
    except:
        print "Access Deny."
    else:
        for fn in ls:
            temp=os.path.join(dirname,fn)
            if (os.path.isdir(temp)):
                dirlist.append(temp)
                WalkDir(dirlist,filelist,temp)
            else:
                filelist.append(temp)
    return dirlist,filelist