How to print a list with the index numbers (python)?

Question

Okay here I go! I am such a noob by the way and I am trying my best to learn. I had to write a little code to open a csv file and format the list such a way that it would work with Libsvm but anyway this is the code I wrote so far :

import csv
with open ('testingSeta.csv')as csvfile:
reader = csv.reader(csvfile, delimiter = ',')
for i in reader:
    i.insert (0, i.pop(13))
    print (" ".join(i))

and this gives me a list like this:

-1 0 1 1 0 1 1 1 4 5 6 5 5 8
-1 0 1 0 0 1 1 1 4 3 7 1 3 6
 1 3 7 2 0 4 4 1 41 46 86 20 18 48
 1 10 11 0 0 6 6 3 26 65 102 25 16 38

testingSeta.csv original format:

0,1,1,0,1,1,1,4,5,6,5,5,8,-1
0,1,0,0,1,1,1,4,3,7,1,3,6,-1
3,7,2,0,4,4,1,41,46,86,20,18,48,1
10,11,0,0,6,6,3,26,65,102,25,16,38,1

I would like the list to be ordered like this:

-1 1:0 2:1 3:1 4:0 5:1 6:1 7:1 8:4 9:5 10:6 11:5 12:5 13:8
-1 1:0 2:1 3:0 4:0 5:1 6:1 7:1 8:4 9:3 10:7 11:1 12:3 13:6
1 1:3 2:7 3:2 4:0 5:4 6:4 7:1 8:41 9:46 10:86 11:20 12:18 13:48
1 1:10 2:11 3:0 4:0 5:6 6:6 7:3 8:26 9:65 10:102 11:25 12:16 13:38

the numbering '1:' should always start from the second number/value. Can any body help? thanks for your time

don't use insert simply slice, you should use also enumerate to index — Padraic Cunningham
– Padraic Cunningham, Commented Jan 11, 2015 at 1:53

jamylak · Accepted Answer · 2015-01-11 02:02:27Z

1

with open('testingSeta.csv') as f:
   for line in csv.reader(f):
      print(' '.join(
                [line[-1]] + 
                ['{0}:{1}'.format(*x) for x in enumerate(line[:-1], start=1)]))


-1 1:0 2:1 3:1 4:0 5:1 6:1 7:1 8:4 9:5 10:6 11:5 12:5 13:8
-1 1:0 2:1 3:0 4:0 5:1 6:1 7:1 8:4 9:3 10:7 11:1 12:3 13:6
1 1:3 2:7 3:2 4:0 5:4 6:4 7:1 8:41 9:46 10:86 11:20 12:18 13:48
1 1:10 2:11 3:0 4:0 5:6 6:6 7:3 8:26 9:65 10:102 11:25 12:16 13:38

answered Jan 11, 2015 at 2:02

jamylak

134k30 gold badges238 silver badges240 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Hackaholic · Accepted Answer · 2015-01-11 01:28:39Z

1

try like this:

>>> with open('your_file') as f:
...     for x in f:
...         line = x.strip().split(',')
...         print "{} ".format(line[-1]) + " ".join("{}:{}".format(i,y) for i,y in enumerate(line[:-1],start=1))
... 
-1 1:0 2:1 3:1 4:0 5:1 6:1 7:1 8:4 9:5 10:6 11:5 12:5 13:8
-1 1:0 2:1 3:0 4:0 5:1 6:1 7:1 8:4 9:3 10:7 11:1 12:3 13:6
1 1:3 2:7 3:2 4:0 5:4 6:4 7:1 8:41 9:46 10:86 11:20 12:18 13:48
1 1:10 2:11 3:0 4:0 5:6 6:6 7:3 8:26 9:65 10:102 11:25 12:16 13:38

answered Jan 11, 2015 at 1:28

Hackaholic

19.8k6 gold badges59 silver badges77 bronze badges

Comments

A human being · Accepted Answer · 2015-01-11 02:12:54Z

1

>>> with open ('testingSeta.csv') as csvfile:
...     reader = csv.reader(csvfile, delimiter = ',')
...     for i in reader:
...         last = i.pop(13)
...         for index,string in enumerate( i ) :
...             i[ index ] = str(index+1) + ":" + string
...         print last + " " + " ".join(i)
... 
-1 1:0 2:1 3:1 4:0 5:1 6:1 7:1 8:4 9:5 10:6 11:5 12:5 13:8
-1 1:0 2:1 3:0 4:0 5:1 6:1 7:1 8:4 9:3 10:7 11:1 12:3 13:6
1 1:3 2:7 3:2 4:0 5:4 6:4 7:1 8:41 9:46 10:86 11:20 12:18 13:48
1 1:10 2:11 3:0 4:0 5:6 6:6 7:3 8:26 9:65 10:102 11:25 12:16 13:38

edited Jan 11, 2015 at 2:12

answered Jan 11, 2015 at 1:40

A human being

1,2208 silver badges18 bronze badges

4 Comments

Ash Over a year ago

OMG OMG OMG UPASANA! YOU ARE AN ANGEL! lankans go hard! thanks so much. much love.

Padraic Cunningham Over a year ago

@Ash You should not use insert a simple end, rest = row[-1:], row[:-1] will extract the last element and all up to the last, and enumerate is pretty much perfect for getting the indexes

Ash Over a year ago

@PadraicCunningham so I should use end, rest = row[-1:], row[:-1] instead of i.insert (0, i.pop(13))??

Padraic Cunningham Over a year ago

@Ash, sorry should be row[-1],row[:-1] row[-1] is the last row element or 13 in your code then row[:-1] is all up to not including the last.

Collectives™ on Stack Overflow

How to print a list with the index numbers (python)?

3 Answers 3

Comments

Comments

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related