[Tutor] line number when reading files using csv module

[Bob Gailer]

Duncan Gibson wrote:
> If I have the following data file, data.csv:
>     1 2 3
>     2 3 4 5
>
> then I can read it in Python 2.4 on linux using:
>
>     import csv
>     f = file('data.csv', 'rb')
>     reader = csv.reader(f)
>     for data in reader:
>         print data
>
> OK, that's all well and good, but I would like to record
> the line number in the file. According to the documentation,
> each reader object has a public 'line_num' attribute
> http://docs.python.org/lib/node265.html and
> http://docs.python.org/lib/csv-examples.html supports this.
>
> If I now change the loop to read:
>
>     for data in reader:
>         print reader.line_num, data
>
> I'm presented with the error:
> AttributeError: '_csv.reader' object has no attribute 'line_num'
>   
Well I get the same exception. dir(reader) does not show line_num.
> This has floored me. I've even looked at the source code and I can
> see the line_num variable in the underlying _csv.c file. I can even
> see the test_csv.py code that checks it!
>
>     def test_read_linenum(self):
>         r = csv.reader(['line,1', 'line,2', 'line,3'])
>         self.assertEqual(r.line_num, 0)
>
> I suspect this is something so obvious that I just can't see the
> wood for the trees and I will kick myself.
>
> Any ideas?
>
> Cheers
> Duncan
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>   


-- 
Bob Gailer
510-978-4454