iterating over a file with two pointers

[Chris Angelico]

On Wed, Sep 18, 2013 at 9:12 PM, nikhil Pandey <nikhilpandey90 at gmail.com> wrote:
> hi,
> I want to iterate over the lines of a file and when i find certain lines, i need another loop starting from the next of that "CERTAIN" line till a few (say 20) lines later.
> so, basically i need two pointers to lines (one for outer loop(for each line in file)) and one for inner loop. How can i do that in python?
> please help. I am stuck up on this.

After the inner loop finishes, do you want to go back to where the
outer loop left off, or should the outer loop continue from the point
where the inner loop stopped? In other words, do you want to locate
overlapping sections, or not? Both are possible, but the solutions
will look somewhat different.

ChrisA