python 使用set对列表去重后，保持原来列表的顺序排列

testlist = ['cc', 'bbbb', 'afa', 'sss', 'bbbb', 'cc', 'shafa']
set2list = list(set(testlist))
print set2list
set2list.sort(key = testlist.index)
print set2list    

运行结果：

['cc', 'shafa', 'bbbb', 'afa', 'sss']
['cc', 'bbbb', 'afa', 'sss', 'shafa']