嘿嘿，慢慢找到写代码的感觉了。

这个小程序涉及的东东还是很多的，数据结构的设计，错误的处理，快速字典排序，文件数值调整。。。。

import os,os.pathimport globSUFFIXES = ['KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB']def approximate_size(size):    '''Convert a file size to human-readable form.    Keyword arguments:    size -- file size in bytes      Returns: string    '''    if size < 0:        raise ValueError('number must be non-negative')    multiple = 1024.0     for suffix in SUFFIXES:        size /= multiple        if size < multiple:            return '{0:.1f} {1}'.format(size, suffix)rootDir = raw_input('Please input root dir:')count = 0fileDict = {}sortfileDict = {}for parent, dirnames, filenames in os.walk(rootDir):    #print('Folder: %s' % dirName)    for filename in filenames:        name = os.path.join(parent,filename)        try:            filesize = os.path.getsize(name)        except (OSError):            filesize = 0        fileDict[name] = filesize        count += 1        print count        sortfileDict = sorted(fileDict.iteritems(), key=lambda fileDict:fileDict[1], reverse = True)fList = open('filelist.txt','w')for i in range(len(sortfileDict)):    #print sortfileDict[i][0], "\t", sortfileDict[i][1]    fileList = "{0} \t {1} \n".format(sortfileDict[i][0], approximate_size(sortfileDict[i][1]))    fList.write(fileList)fList.close()print 'DONE'