如何从列表列表中的列表中提取最后一项？ (Python)

Question

我有一个列表列表，想提取最后的项目并将它们放在列表列表中。提取最后一项相对容易。但是我所有的尝试都会产生一个列表，而不是列表列表。有什么建议吗？

lst = [[[11, 12, 15], [12, 13, 14], [13, 14, 15], [14, 15, 17], [15, 16, 17]], [[14, 15, 18], [15, 16, 17]]]

我想要的结果是：[[15, 14, 15, 17, 17], [18, 17]]

例如我试过的是这个函数：

def Extract(lst): 
    for i in lst:
        return [item[-1] for item in i]
print(Extract(lst))

但这只会给出：[15, 14, 15, 17, 17]

我也试过：

last = []
for i in lst:
    for d in i:
        last.append(d[-1])
last

但这给出了：[15, 14, 15, 17, 17, 18, 17]

关于如何得到 [[15, 14, 15, 17, 17], [17, 18]] 作为结果有什么建议吗？

Answer 1

lst = [[[11, 12, 15], [12, 13, 14], [13, 14, 15], [14, 15, 17], [15, 16, 17]], [[14, 15, 18], [15, 16, 17]]]

out = [[l[-1] for l in v] for v in lst]
print(out)

打印：

[[15, 14, 15, 17, 17], [18, 17]]

Answer 2

我建议循环遍历列表两次，如下所示：

lst = [[[11, 12, 15], [12, 13, 14], [13, 14, 15], [14, 15, 17], [15, 16, 17]], [[14, 15, 18], [15, 16, 17]]]

# Result of iteration
last_lst = []

# Iterate through lst
for item1 in lst:
    # Initialize temporary list
    last_item1 = []
    
    #Iterate through each list in lst
    for item2 in item1:
        # Add last item to temporary list
        last_item1.append(item2[-1])
        
    # Add the temporary list to last_lst
    last_lst.append(last_item1)

如何从列表列表中的列表中提取最后一项？ (Python)

How to extract the last item from a list in a list of lists? (Python)

python-3.x

list

sublist