On Mon, May 3, 2010 at 1:49 AM, Stefan Behnel <stefan...@behnel.de> wrote:
>
> You are modifying the list during iteration, so the size changes and the
> iterator gets diverted. Don't remove the line, just skip over it, e.g.
>
> def read_package_names(open_text_file):
> """Read lines, strip any comments and return only the
> package names found.
> """
> for line in open_text_file:
> if '%' in line:
> # take only the part before the '%'
> line = line.split('%', 1)[0]
> line = line.strip()
> if line:
> yield line
And here if you wanted all the text on the line before the first '%'
as a list comprehension it would be something like this:
lines = [line[:line.index('%')] for line in lines if not
line.strip().startswith('%')]
>
> with open('packages.txt') as f:
> for package_name in read_package_names(f):
> print package_name
>
What's this bizarre syntax?
I thought they changed for loop interations so that if you did
for line in open('packages.txt'):
.... etc...
it would automatically close the file handle after the loop terminated.
Have I been wrong this whole time?
-Luke
_______________________________________________
Tutor maillist - Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
