如何根据条件从列表中获取元素及其索引？

Question

我有一个具有重复值的列表，我找到了最大长度的列表，但是我想获取这些最大列表的索引并将它们添加到我的索引列表中。

mylist = [{'destination', 'graph'}, {'vertex'}, {'destination', 'modify'}, {'destination', 'modify'}, {'modify', 'return'}, {'destination'}]

max_len = len(sorted(mylist, key=lambda x: len(x), reverse=True)[0])
uniq_list = [k for k in mylist if len(k) == max_len]
print(uniq_list)

当前输出：

[{'destination', 'graph'}, {'destination', 'modify'}, {'destination', 'modify'}, {'modify', 'return'}]

预期输出：

[{'destination', 'graph'}, {'destination', 'modify'}, {'destination', 'modify'}, {'modify', 'return'}]

index_list = [0,2,3,4]

Answer 1

使用enumerate将子列表和索引都保留在元组中，并用zip解压缩它们：

out = ((ix, k) for ix, k in enumerate(mylist) if len(k) == max_len)
index_list , uniq_list = zip(*out)

print(index_list)
# (0, 2, 3, 4)

print(uniq_list)
#({'graph', 'destination'}, {'modify', 'destination'}, 
# {'modify', 'destination'}, {'modify', 'return'})