在保持顺序的同时删除二维数组中的重复项
问题描述：
我发现有很多线程可以删除数组中的重复项，但对于我的特定用例却没有。我有一个二维列表，我需要从中删除重复项，但是我必须保持原始顺序
I have found a lot of threads on removing duplicates in arrays but none for my specific use-case. I have a two-dimensional list that I need to remove duplicates from however I must maintain the original sequence
mylist = [['Installation', '64%'], ['C2', '14%'], ['NA', '14%'], ['C2', '14%'], ['NA', '14%'], ['na', '7%']]
我只需要删除重复项
newlist = [['Installation', '64%'], ['C2', '14%'], ['NA', '14%'], ['na', '7%']]
感谢任何帮助
答
使用 set 来跟踪可见项目：
Using set to keep track of seen items:
>>> mylist = [['Installation', '64%'], ['C2', '14%'], ['NA', '14%'], ['C2', '14%'], ['NA', '14%'], ['na', '7%']]
>>> seen = set()
>>> newlist = []
>>> for item in mylist:
... t = tuple(item)
... if t not in seen:
... newlist.append(item)
... seen.add(t)
...
>>> newlist
[['Installation', '64%'], ['C2', '14%'], ['NA', '14%'], ['na', '7%']]
注意
您需要将列表转换为元组（列表不可散列）；
You need to convert a list to tuple (list is not hashable); can't add a list to set.
>>> seen = set()
>>> seen.add([1,2])
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: unhashable type: 'list'
>>> seen.add(tuple([1,2]))
>>>