排序从最高到最低没有内置

Question

如何编写一个排序功能，从最高到最低排序，没有内置函数？

例如：

A=[2,4,6] 
sorthightolow(A) 
A=[6,4,2] 

Answer 1

我不知道为什么人们会做没有内置功能，但这里的工作冒泡排序的例子。 http://rosettacode.org/wiki/Sorting_algorithms/Bubble_sort#Python

def bubble_sort(seq): 
    """Inefficiently sort the mutable sequence (list) in place. 
     seq MUST BE A MUTABLE SEQUENCE. 

     As with list.sort() and random.shuffle this does NOT return 
    """ 
    changed = True 
    while changed: 
     changed = False 
     for i in xrange(len(seq) - 1): 
      if seq[i] > seq[i+1]: 
       seq[i], seq[i+1] = seq[i+1], seq[i] 
       changed = True 
    return seq 

if __name__ == "__main__": 
    """Sample usage and simple test suite""" 

    from random import shuffle 

    testset = range(100) 
    testcase = testset[:] # make a copy 
    shuffle(testcase) 
    assert testcase != testset # we've shuffled it 
    bubble_sort(testcase) 
    assert testcase == testset # we've unshuffled it back into a copy