用python对指定目录下的所有文件（夹）大小进行排序

Windows的某个目录下sort by size只能对该目录下的文件进行排序，不能对目录下的文件夹进行排序，而手工点击右键逐个计算文件夹的大小效比较低。在此我用用python对指定目录下的所有文件（夹）大小进行排序，代码如下：

#! /usr/bin/env python
'''
Sort the size of floders and files with given directory.
Author: Sean.Xu
'''
import os
import os.path
import datetime

L={}
k={}
rootdir = 'C:\\Windows'

def getdirsize(dir):
    size = 0

    for parent, dirnames, filenames in os.walk(dir):
        for filename in filenames:
            try:
                name = os.path.join(parent, filename)
                size += os.path.getsize(name)
            except:
                continue

    return size

def getsizename(size):
    if (size > 1024*1024*1024.0):
        numstr = str(size/(1024*1024*1024.0))
        sizename = numstr[:(numstr.index('.')+3)]+'GB'
    elif (size > 1024*1024.0):
        numstr = str(size/(1024*1024.0))
        sizename = numstr[:(numstr.index('.')+3)]+'MB'
    elif (size > 1024.0):
        numstr = str(size/1024.0)
        sizename = numstr[:(numstr.index('.')+3)]+'KB'
    else:
        sizename = str(size) +'Bytes'

    return sizename

# proc start
starttime = datetime.datetime.now()

filenames = os.listdir(rootdir)
for filename in filenames:
    fullpath = os.path.join(rootdir, filename)
    if os.path.isdir(fullpath):
        L[filename] = getdirsize(fullpath)
    else:
        L[filename] = os.path.getsize(fullpath)

k = sorted(L.items(), key=lambda L:L[1], reverse = True)
endtime = datetime.datetime.now()

print 'The directory of %s has %d items(folder and file).' %(rootdir, len(k))
print 'It took %ds to sort the size of these items. The result is as below:' %(endtime - starttime).seconds

for i in range(len(k)):
    print k[i][0],"\t",getsizename(k[i][1])

示例中是对C的Windows目录下的文件（夹）进行排序，部分结果如下：

D:\python_example>sortfilesize.py
The directory of C:\Windows has 131 items(folder and file).
It took 68s to sort the size of these items. The result is as below:
Installer       14.30GB
WinSxS  3.92GB
System32        2.35GB
assembly        849.10MB
Microsoft.NET   387.80MB
Fonts   376.48MB
Panther         180.95MB
Symbols         167.64MB
IME     165.17MB
SoftwareDistribution    150.48MB
SystemApps      116.69MB
Speech  110.44MB
INF     73.98MB
Speech_OneCore  50.81MB
servicing       48.02MB
InputMethod     34.57MB
Boot    30.72MB
Performance     28.19MB
Media   26.35MB
......

花了68秒对该目录下的131个文件(夹）进行了排序，并且显示了大小，结果一目了然。