在python中排序列表(sorting a list in python)

 我正在尝试对列表中的列表进行排序：每个列表包含[seq1,seq2,score] ，我想根据（seq1，seq2）的得分从最高得分到最低得分对列表L进行排序，然后每个列表根据得分对每个（seq1，seq2）进行排名 
 
L=[ ['AA', 'CG', 0],['AA', 'AA', 4], ['CG', '--', -1]]
 
 排序列表必须是： 
 
L=[['AA', 'AA', 4], ['AA', 'CG', 0], ['CG', '--', -1]]
 
 为队伍： 
 
['AA', 'AA', 4] has rank 1
['AA', 'CG', 0] has rank 2
['CG', '--', -1] has rank 3
 
 我该怎么做？ 我试过了： 
 
def getKey():/* to get the score from each list*/
    scorelist=score()/*this is the list L*/
    return scorelist[][2]



def sort_list():
   scorelist=score()
    p=sorted(s, key=getKey)
    return p

I am trying to sort lists on a list : each list contains [seq1,seq2,score] , I want to sort the list L according to the score of (seq1,seq2) from the max score to the minimum score, then each list take a rank to each (seq1,seq2) according to the score
 
L=[ ['AA', 'CG', 0],['AA', 'AA', 4], ['CG', '--', -1]]
 
the sorted list must be:
 
L=[['AA', 'AA', 4], ['AA', 'CG', 0], ['CG', '--', -1]]
 
for the ranks:
 
['AA', 'AA', 4] has rank 1
['AA', 'CG', 0] has rank 2
['CG', '--', -1] has rank 3
 
how can I do it? I tried:
 
def getKey():/* to get the score from each list*/
    scorelist=score()/*this is the list L*/
    return scorelist[][2]



def sort_list():
   scorelist=score()
    p=sorted(s, key=getKey)
    return p

原文：