def two_sum(lst, target):
indexes = {}
for i, num in enumerate(lst):
val = target - num
if val in indexes:
return [indexes[val], i]
else:
indexes[num] = i
return []
lst = [1, 5, 7, 6, 4, 3, 2]
target = 9
result = two_sum(lst, target)
print(result)
'''
run:
[1, 4]
'''