[Tutor] Trying to extract the last line of a text file

[Chris Hengge]

I dont care for slow... I dont use computers with less then 1gb of ram..
(all my systems have 2gb), I hate to wait... =D If I've got memory to use, I
intend to use it!

As for reading 100 20mb files, I'd do one at a time, then dump the variable
storing the data, or reset/re-use. Just my take though.

On 10/19/06, Luke Paireepinart <rabidpoobear at gmail.com> wrote:
>
> Chris Hengge wrote:
> > I thought my solution was the easiest.. but I guess everyone skipped it
> =P
> No, we didn't skip it,
> but as we're all programmers here, we showed alternate ways that it
> could be done.
> Your post is the one that sparked the whole 'garbage collection' thing,
> you'll notice.
>
> Now, I don't want to be left out of the loop on this,
> and the first thing I thought of when I read his question about how to
> read the last line was:
> Well, what if he wants to read the last line of 100 20 mb files?
> Does he really want to read all of these into memory just to get the
> last line?
> I wouldn't think so!
> So I've made an alternate solution using seek.
> The last line can't be more than 1000 chars long, or whatever the Python
> maximum recursion depth happens to be at runtime,
> but you could easily change this into a non-recursive implementation if
> you so desired.
> I just wanted to be cool :)
>
> #read_last_line.py
> f = file('wii.txt','r')
> f.seek(-1,2)#start at end of file.
> if f.read(1) == '\n':#if file ends with a newline:
>     f.seek(-3,1)#start at right before the newline.
> else:
>     f.seek(-1,1)#just start at the end.
> def prevchar(fileobj):
>     achar = fileobj.read(1)
>     if achar == '\n': return ''
>     else:
>         fileobj.seek(-2,1)
>         return prevchar(fileobj)+achar
> print prevchar(f)
>
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