On 28 January 2013 11:47, loial <jldunn2...@gmail.com> wrote:
> I am parseing a file to extract data, but am seeing the file being updated
> even though I never explicitly write to the file. It is possible that another
> process is doing this at some later time, but I just want to check that
> opening the file as follows and ignoring a record would not result in that
> record being removed from the file.
>
> I'm damned sure it wouldn't, but just wanted to check with the experts!.
>
>
> for line in open("/home/john/myfile"):
The line above opens the file in read-only mode. It's not possible to
make changes to the file if you only open it in read-only mode. So no
this code is not modifying the file. It is, however, slightly better
to write the above as
with open('/home/john/myfile') as fin:
for line in fin:
# stuff
This is better as the "with" statement handles errors better than just
calling open directly.
> linecount = linecount + 1
>
> if linecount == 1: # ignore header
> continue
Another way of achieving this would be to do:
headerline = fin.readline()
for line in fin:
# No need to worry about that header line now
Oscar
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