Multiplying sequences with floats

[Caleb Hattingh]

Hi Fredrik

Fair enough; I wasn't precise.  Upon further reflection, I actually
meant floor division, via the // operator.  In the following snippet:

>>> 4/2
2
>>> 4//2
2
>>> 4.0/2.0
2.0
>>> 4.0//2
2.0
>>> 4.0//2.0
2.0

We know the last two operations can only return what are effectively
integer numbers (or raise an error), but the type that gets returned
for a valid operation is a float.   Now, I'm not pretending to know
much about this stuff, just pointing out that that behaviour is
interesting.    Just like how MvL pointed out to me in a recent thread
that in certain cases .read().splitlines(True) is significantly faster
than .readlines() on some file objects: that's interesting.

I am sure there are good reasons for this, and I can't imagine that the
issue of return type didn't come up when discussions about the floor
division operator was discussed;  in fact, thinking about it a little
more, I suspect this operator is probably more likely to be used in a
sequence of floating-point operations anyway, for which the current
implementation saves a type conversion that might have been necessary
had it been made to return int to start with.

So regarding my previous statement:

>> I agree that integer division should return an integer,
>> because using the operator at all means you expect one.

I am not so sure now :)

By the way (regarding PIL), have you seen this site:
http://www.greyc.unicaen.fr/~dtschump/greycstoration/index.html

It is an open-source project implementing fancy methods for cleaning up
images and (my interest) resizing images with better clarity on
enlargements.  I had been working on a python implementation for this
kind of thing with heavy leaning on the PIL, but I saw this project on
the daily freshmeat newsletter, and so will probably use that code
instead.

regards
Caleb