How would I read a list from text file?

Question

I tried this:

saves = open('filename','r')
Y = saves.readlines()
print(Y)

but I get the output [b'[0, 0, 0, 0, 0,]'] instead of [0, 0, 0, 0, 0,]

The text file content is [0, 0, 0, 0, 0]

(This not duplicate as the question is about something else and the answer didn't help me)

you can transform data by this way: Y = [eval(x) for x in Y] — Denis Kuzin, Jun 17 '17 at 13:43
@DenisKuzin `eval` is never a good method to use, in any situation. — cs95, Jun 17 '17 at 13:47

cs95 · Accepted Answer · 2017-06-17T14:06:53.430

0

Use the Json module.

import json
Y = json.load(open('filename','r'))
print(Y)

Output

[0, 0, 0, 0, 0]

Demo:

>>> import json
>>> open('f.txt', 'w').write('[0, 0, 0, 0, 0]')
>>> y = json.load(open('f.txt', 'r'))
>>> y
[0, 0, 0, 0, 0]

edited Jun 17 '17 at 14:06

answered Jun 17 '17 at 13:41

cs95

that throws up lot's of errors – Qwertykey Jun 17 '17 at 13:43
@Qwertykey Might want to be specific about those errors... :) – cs95 Jun 17 '17 at 13:44
Expecting value: line 1 column 16 (char 15) - that's the error – Qwertykey Jun 17 '17 at 13:48
@Qwertykey Yeah I got it. Your text file has an extra `,` (comma). Observe: `[0, 0, 0, 0, 0,]` (this last comma needs to go.) – cs95 Jun 17 '17 at 13:49
still prints with double brackets – Qwertykey Jun 17 '17 at 13:51
@Qwertykey In that case, your text file contents are different from what you claim them to be. I have tried this with the exact same input you mentioned in your post and got exactly what I put in my answer. Henceforth, please be clear with your question. – cs95 Jun 17 '17 at 13:59
in the text file it literally just says [0, 0, 0, 0, 0] – Qwertykey Jun 17 '17 at 14:06
@Qwertykey I've edited my post to add a demo. Please try it out and see what you get. Which python are you using? In the worst case just do `Y[0]` to remove the double brackets. – cs95 Jun 17 '17 at 14:07
your method works, i forgot to change something and that's why the error happened – Qwertykey Jun 17 '17 at 14:08
@Qwertykey Ah, no worries. Happens to us all. – cs95 Jun 17 '17 at 14:09

1 Answers1