[Tutor] readlinesX

[Kalle Svensson]

Sez Shawhan, Douglas (GEAE, GECC):
> I have been scouting around on the python.org site looking for references
> to readlineX. Where can I find the whole poop on this function?

That would be xreadlines?
There is no good documentation at the moment, but here's what I know:

The below applies to the function xreadlines in the module xreadlines, and
the file object method xreadlines.
It returns a sequence object, much like the list returned by readlines, only
it doesn't read all the lines into memory but reads them "on demand"
(reading ahead a bit for performance, I think).

Thus, it's now possible to do

for line in file.xreadlines(): # formerly file.readlines()
    # do stuff with line

without reading the entire file into memory.  This does away with

while 1:
    line = file.readline()
    if not line:
        break
    # do stuff with line

which is sort of ugly.

The above is IIRC, AFAIK and IMHO.

Peace,
  Kalle
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