编写类du命令Python脚本

 #!/usr/bin/env python
 #_*_ coding:utf-8 _*_
 #计算整个目录的大小,脚本接受-H参数，来加上适当的单位
 #功能像du看齐

 import os,sys
 from optparse import OptionParser

 def option():
         parser = OptionParser()
         parser.add_option('-H','--Human',dest='human',action='store_true',default=False,help='print sizes in human readable format')
         option,args = parser.parse_args()
         return option,args

 def findfile(dirpath):
     path = os.walk(dirpath)
     for roots,dirs,files in path:
         for file in files:
                 yield os.path.join(roots,file)

 def filesize(option,file):
         size = os.path.getsize(file)
         if not option:
             return str(size)
         else:
             if size >= 1024000000:
                 return str(size/1024/1024/1024) + 'G'
             elif size >= 1024000:
                 return str(size/1024/1024) + 'M'
             elif size >= 4096:
                 return str(size/1024) + 'K'
             else:
                 return '4.0K'

 def main():
         options,args = option()
         try:
                 path = args[0]
         except IndexError as e:
                 sys.exit('%s need a directory' % __file__)
         for file in findfile(path):
                 size = filesize(options.human,file)
                 print size,file

 if __name__ == '__main__':
     main()