[Tutor] << operator ? [left bitwise shifting]
Prahlad Vaidyanathan
slime@vsnl.net
Fri, 12 Apr 2002 04:29:25 -0400
Hi,
Thanks to all for their explanations. But, let me prod a little further
(OT) ...
On Wed, 10 Apr 2002 Danny Yoo spewed into the ether:
[-- snippity --]
> And this is what we mean when we say that computers count in base-two
> arithmetic --- they represent numbers by using on/off switches --- "bits".
> On most systems that Python runs on, each integer is made up of 32 bits.
Hmm .. is this the difference between the computers used popularly
today, and the new IA-64 architecture ? If so, does a "2" on a 64-bit
machine have 32 more zeroes in front of it, than a "2" on a 32-bit
machine ?
> It turns out that bits are really useful because we don't have to say that
> 32 bits always stand for a number: we can use those bits as 32 individual
> "yes/no" choices!
Ahh .. now I remember the Boolean Algebra we did in school. Ok, that
clears it up nicely :-)
> Here's a concrete example: the Unix operating system uses numeric codes to
> say if a particular file is readable, writable, or executable --- each
> file has a "permission" number connected to it. The number "7", for
> example, has the following bit representation:
[-- snippity --]
Ok. I think I've got a hang of what these operators do. Now to go find
a binary file to play with in "pure" python .... :-)
pv.
--
Prahlad Vaidyanathan <http://www.symonds.net/~prahladv/>
The appreciation of the average visual graphisticator alone is worth
the whole suaveness and decadence which abounds!!