[Tutor] Binary math?

[Jeffrey Thomas Peery]

Thanks for the help. Well I am aware of how computers use binary and such,
although I have to do a little arithmetic with binary numbers, I am an
engineer and I have some test data that is in hexadecimal and I need to
convert that to binary and that to regular base ten numbers. I was hoping
that there was a python module or commands that would do the binary
addition/subtraction multiplication and such. I wrote a program that seems
to work ok for what I need but I used a lot of code to do it, I was hoping
for something easier to read. If you have any thoughts please let me know.
Thanks.

J

-----Original Message-----
From: Danny Yoo [mailto:dyoo at hkn.eecs.berkeley.edu] 
Sent: Monday, October 25, 2004 11:01 AM
To: Jeff Peery
Cc: tutor at python.org
Subject: Re: [Tutor] Binary math?



On Mon, 25 Oct 2004, Jeff Peery wrote:

> will python work with binary math?

Hi Jeff,

Just to clarify: most computers work on the principle of binary.  There's
a layer of abstraction that hides the bit-twiddling from us.  When we say
something like 42, the computer is using a bit pattern to represent the
number 42:

    42   <====>  101010

                (2**5 + 2**3 + 2**1)

Python (and most computer systems) will do work using the bit-patterns,
and a separate program converts those bit-patterns back into a decimal
representation that's comfortable for humans.



> i.e., add subtract binary numbers? is there a specific type that I have
> to use to define a binary number? thanks.

What are you trying to do?  If you're trying to understand how binary math
works, I'd recommend looking at "Code":

    http://www.charlespetzold.com/code/index.html


And if you have a string with the proper bit pattern, then you can use the
int() builtin:

###
>>> int('101010', 2)
42
###


But I have to admit: I'm still a little confused at what you're asking.
Please tell us more why you're trying to do binary arithmetic, so we can
give better help.

Good luck to you!