[BangPypers] How to handle files efficiently in python

[Pradeep Gowda]

On Tue, Mar 22, 2011 at 12:49 PM, Noufal Ibrahim <noufal at gmail.com> wrote:
> On Tue, Mar 22 2011, brijithp at gmail.com wrote:
>
>> Hi All,
>>         How can I print last five lines of a file using python. The file may
>> contain thousands of lines each line may differ in length.
>
> [...]
>
> You'd have to use some kind of heuristic (a.k.a. dirty hack). Stat the
> file to find it's size and use an "average" length of line to go a few
> lines back. Then count the number of newlines from there to the end. If
> it's 4, then you have your 5 lines. Otherwise, seek back a little more
> and repeat.

Negative file.seek does not work on Text files [1]

[1] http://mail.python.org/pipermail/python-bugs-list/2008-August/057225.html