Different value from .txt for every loop (Python)

Question

I have to change the res variable value in the next code for every loop it does.

txt = open(os.path.expanduser('~FOLDER\\numbers.txt'), 'r')
res = txt.read().splitlines()

u = [something]    
for item in u:
    var['Number : ' + res[0]]

txt variable contains a text file. In this text file there some lines of numbers in this format:

I have to take a variable for each loop the script does and assign to res. At the moment, with res[0] it only iterate the same number (ex: 123) on every loop. How can I solve the problem ? It should be 0 at first, 1 at second ad so on...

you set `u` to `[]` and then iterate over it. this will not work. i think you made a copy&paste error here. — mnagel, Oct 17 '17 at 15:42
you assign u with an empty array and then iterate over it (which is empty) — StefanE, Oct 17 '17 at 15:44
What is the point of iterating `item in u` if within the `for` you never use `item`? — pstatix, Oct 17 '17 at 15:45
res[0] will always return 123. You have to increment res[1] to get the next res element in the list. — Ron Norris, Oct 17 '17 at 15:46
@Link Dont post partial code. If you came to a mechanic with a car problem, but didnt show up with the car, how can they fix it? — pstatix, Oct 17 '17 at 15:50

score 1 · Answer 1 · answered Oct 17 '17 at 15:54

1

I think this should do the job :

with open(os.path.expanduser('~FOLDER\\numbers.txt'), 'r') as res: for line in res: var['Number ': line]

More info here

answered Oct 17 '17 at 15:54

Romain B.

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score 0 · Accepted Answer · answered Oct 17 '17 at 15:47

0

txt = open(os.path.expanduser('~FOLDER\\numbers.txt'), 'r')
res = txt.read().splitlines()

u = [something]    
for index, item in enumerate(u):
    var['Number : ' + res[index]]

More info about enumerate here: https://docs.python.org/2/library/functions.html#enumerate

answered Oct 17 '17 at 15:47

StefanE

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"index" don't have to be initialized above u? – lucians Oct 18 '17 at 14:50
Index can only be used within the for loop – StefanE Oct 18 '17 at 16:59

score 0 · Answer 3 · answered Oct 17 '17 at 15:50

I assume you want to iterate through u and v simultaneously. In this case, you either want to just use a plain index using for loop over a range, or you could use enumerate as follows:

txt = open(os.path.expanduser('~FOLDER\\numbers.txt'), 'r')
res = txt.read().splitlines()

u = [something]    
for index, item in enumerate(u):
    var['Number : ' + res[index]]

Different value from .txt for every loop (Python)

3 Answers3