Python 3x TypeError：列表索引必须是整数或切片，而不是 str

Question

I'm currently making a program which will compress a user sentence into two variables unique_words and positions. Unique words will be all the unique words from the user's sentence, so for example "the cat sat on the mat" the unique words will be "the, cat, sat, on, mat" and the positions will be 123415. I'm saving both of these in a text file.

I'm fairly new to coding, therefore I preferably would not want to use dictionaries as I believe it would make it so my code will not be able to keep capitalisation and punctuation.

Then what I want to be able to do is extract these back from the text file, and store them in two separate variables, so for example I want my code to look something like so:

list_1 = [the, cat, sat, on, mat]
list_2 = [1, 2, 3, 4, 1, 5]
list_3 = []

for i in list_2:
  list_3.append(list_1[i])

However when I do this in my actual code:

for l in positions_File:
        orig_sntnce.append(uqwordsFile[l])
    print(orig_sntnce)`

I get the error TypeError: list indices must be integers or slices, not str I think I need to somehow convert my list that contains the unique words into a 'slice'? I'm really stuck on how to do this? I've tried splitting the list but I think this would again, make it so I will not be able to keep punctuation and capitalisation of the original sentence.

Answer 1

list_1 元素应该是字符串，即 list_1 = ['the', 'cat', 'sat', 'on', 'mat']，缺少单引号/双引号，还可以看到 list_2 有 5 作为元素导致错误，因为 list_1 只有 5 个元素，因此它只能从 0,4 索引。