Return Python 列表中每个子列表的大于 k 的数字索引

Question

输入：在子列表中查找大于 50 的数字索引

a = [[10,40,90],[120,30,200],[70,90,100]]

期望的输出：

index_of_values_greater_than_50 = [[2][0,2][0,1,2]]

Answer 1

output_list = []

a = [[10,40,90],[120,30,200],[70,90,100]]

for array in a:
   counter = 0
   new_list = []
   while counter < len(array):
      if array[counter] > 50:
         new_list.append(counter)
      counter += 1
   output_list.append(new_list)

print(output_list)

输出（根据需要）：

[[2], [0, 2], [0, 1, 2]]

Answer 2

index_of_values_greater_than_50 = []
for x in a:
 temp = [i for i, y in enumerate(x) if (y>50)
 index_of_values_greater_than_50.append(temp)

Return Python 列表中每个子列表的大于 k 的数字索引

Return index of numbers greater than k for each of sublists in list in Python

python

list

nested-lists

python-2.7