示例列表：

sample_list = [(5,16,2),(5,10,3),(5,8,1),(21,24,1)]

上面前3個元組有類似的第一個元素5，在這種情況下，只有第二個元組應該保留，因為它有最大的最后一個元素=> 3。

輸出結果：

result = [(5,10,3),(21,24,1)]

1、使用defaultdict實現

參考文檔：defaultdict 

from collections import defaultdictsample_list = [(5,16,2),(5,10,3),(5,8,1),(21,24,1)]d = defaultdict(list)for e in sample_list:    d[e[0]].append(e)res = [max(val, key=lambda x: x[2]) for val in d.values()]print(res)

2、使用itertools.groupby 和 operator.itemgetter 實現

參考文檔：

itertools.groupby 

operator.itemgetter 

max

from itertools import groupby
from operator import itemgetter as ig
lst = [(5, 10, 3), (21, 24, 1), (5, 8, 1), (5, 16, 2)]
[max(g, key=ig(-1)) for _, g in groupby(sorted(lst), key=ig(0))]
# [(5, 10, 3), (21, 24, 1)]

3、使用itertools.groupby實現

參考文檔：itertools.groupby

rom itertools import groupbysample_list.sort()print([max(l, key=lambda x: x[-1]) for _, l in groupby(sample_list, key=lambda x: x[0])])

4、使用operator.itemgetter實現

參考文檔：operator.itemgetter

from itertools import groupbyfrom operator import itemgettersample_list = [(5,16,2),(5,10,3),(5,8,1),(21,24,1)]sample_list.sort()print([max(l, key=itemgetter(-1)) for _, l in groupby(sample_list, key=itemgetter(0))])

或者

from operator import itemgettersample_list = [(5,16,2),(5,10,3),(5,8,1),(21,24,1)]dct = {}for i in sample_list:    if i[0] in dct:        dct[i[0]].append(i)    else:        dct[i[0]] = [i]print([max(v, key=itemgetter(-1)) for v in dct.values()])