# -*- coding: utf-8 -*-

 """

 Created on Tue Oct 10 09:04:53 2017

 @author: nvidia

 """

 #!/usr/bin/python

 #coding=utf-8

 #求一个集合的所有真子集

 def getRealSubSet(fromList,toList):

   if(len(fromList) <= 1):

   return

   for id in range(len(fromList)):

   arr = [i for i in fromList if i != fromList[id]]

   getRealSubSet(arr,toList)

   #print arr

   if(toList.count(arr) == 0):

   toList.append(arr)

 li = []

 getRealSubSet([3,4,5],li)

 li.sort()

 print li

 #以上为第二题答案

 #after charging ,it was all right!

 """

 the down words are the result!

 Python 2.7.12 (default, Nov 19 2016, 06:48:10)

 Type "copyright", "credits" or "license" for more information.

 IPython 2.4.1 -- An enhanced Interactive Python.

 ? -> Introduction and overview of IPython's features.

 %quickref -> Quick reference.

 help -> Python's own help system.

 object? -> Details about 'object', use 'object??' for extra details.

 %guiref -> A brief reference about the graphical user interface.

 In [1]: runfile('/home/nvidia/Documents/work/20171010.py', wdir='/home/nvidia/Documents/work')

 [[3], [3, 4], [3, 5], [4], [4, 5], [5]]

 In [2]: 

 """