为什么我在 python 中收到错误“TypeError: 'NoneType' object is not subscriptable”？

Question

I'm iterating over a list of tuples and assigning the values in the tuple to a string. Why do i get an Error here?

for x in falsy_instances:
            instance_list += 'InstanceId: ' + x[0] + ' -> ' + str(x[1]) + 'h\n'

My list of tuples looks like this:

[('i-048debd640ac2dc2f', 2303), ('i-097fc609b8b4dfd56', 5177), ('i-0ba0bb267b314277e', 1913), ('i-09ee8e071c20a7c3d', 4030), ('i-061a71ea52275f17b', 1406), None, ('i-02a7c2e0335dc7b3c', 144), ('i-02e7f7f17726ca422', 2538), ('i-0f18e9ae7728be9b3', 2198)]

Here is my output

Answer 1

The 6th element in your list is None :

[('i-048debd640ac2dc2f', 2303),
 ('i-097fc609b8b4dfd56', 5177),
 ('i-0ba0bb267b314277e', 1913),
 ('i-09ee8e071c20a7c3d', 4030),
 ('i-061a71ea52275f17b', 1406),
 None,  # <-- Here
 ('i-02a7c2e0335dc7b3c', 144),
 ('i-02e7f7f17726ca422', 2538),
 ('i-0f18e9ae7728be9b3', 2198)]

Answer 2

for x in falsy_instances:
  if x is not None:
    instance_list += 'InstanceId: ' + x[0] + ' -> ' + str(x[1]) + 'h\n'