Bitmask representation of integers

[Tonguç Yumruk]

Hi,

I'm looking for a way to represent bit-level data in python. Something
like 0xDEADBEEF representation, but not for hex i'm looking for binary.
Something like the %00110101 representation I used in pascal... Of
course I can make my operations with ordinary integers but binary
representation makes the code easier to read.

--
Love, Respect, Linux
############### ############### ############### ############### ############### #[color=blue]
> I've hacked the Xaw3d library to give you a Win95 like interface and it
> is named Xaw95. You can replace your Xaw3d library.[/color]
Oh God, this is so disgusting!
-- seen on c.o.l.developme nt.apps, about the "Win95 look-alike"
############### ############### ############### ############### ############### #
Tonguç Yumruk

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.2 (GNU/Linux)

iD8DBQE/g7FE1xWu4MLSyoY RAtrkAJ0XHQ+cLh E64NQnCzgYLQO6i KYufgCfa8nl
3Y2jbiBhXOWtc8C Ub/cGzpk=
=kxv0
-----END PGP SIGNATURE-----

[Peter Abel]

Re: Bitmask representation of integers

Tonguç Yumruk <trooper@ttnet. net.tr> wrote in message news:<mailman.1 065595274.17690 .python-list@python.org >...[color=blue]
> Hi,
>
> I'm looking for a way to represent bit-level data in python. Something
> like 0xDEADBEEF representation, but not for hex i'm looking for binary.
> Something like the %00110101 representation I used in pascal... Of
> course I can make my operations with ordinary integers but binary
> representation makes the code easier to read.
>
> --
> Love, Respect, Linux
> ############### ############### ############### ############### ############### #[color=green]
> > I've hacked the Xaw3d library to give you a Win95 like interface and it
> > is named Xaw95. You can replace your Xaw3d library.[/color]
> Oh God, this is so disgusting!
> -- seen on c.o.l.developme nt.apps, about the "Win95 look-alike"
> ############### ############### ############### ############### ############### #
> Tongu Yumruk
>
> --[/color]
[color=blue][color=green][color=darkred]
>>> a=255
>>> b=0xff
>>> c=int('FF',16)
>>> d=int('11111111 ',2)
>>> a,b,c,d[/color][/color][/color]
(255, 255, 255, 255)[color=blue][color=green][color=darkred]
>>>[/color][/color][/color]

Regards
Peter

[Miki Tebeka]

Re: Bitmask representation of integers

Hello Tonguç,
[color=blue]
> I'm looking for a way to represent bit-level data in python. Something
> like 0xDEADBEEF representation, but not for hex i'm looking for binary.
> Something like the %00110101 representation I used in pascal... Of
> course I can make my operations with ordinary integers but binary
> representation makes the code easier to read.[/color]
Just use strings.[color=blue][color=green][color=darkred]
>>> int("101", 2)[/color][/color][/color]
5[color=blue][color=green][color=darkred]
>>>[/color][/color][/color]

HTH.
Miki

[Scott David Daniels]

Re: Bitmask representation of integers

Tonguç Yumruk wrote:[color=blue]
> Hi,
>
> I'm looking for a way to represent bit-level data in python. Something
> like 0xDEADBEEF representation, but not for hex i'm looking for binary.
> Something like the %00110101 representation I used in pascal... Of
> course I can make my operations with ordinary integers but binary
> representation makes the code easier to read.
>[/color]
octal is a simple starting point:

_octalchunks = '000', '001', '010', '011', '100', '101', '110', '111'

_encoder = dict(enumerate( _octalchunks))
_decoder = dict([(txt, str(n)) for n, txt in _encoder.items( )
+ [(0,''), (0,'0'), (1,'1'),
(0,'00'), (1,'01'), (2,'10'), (3,'11')]])

def tobinary(number ):
initial = ''.join([_encoder[digit] for digit in oct(number)])
# but the above certainly has too many leading zeroes, so:
return initial.lstrip( '0') or '0'


def frombinary(text ):
firstdigitlen = len(text) % 3
digits = [_decoder[text[n:n+3]]
for n in range(firstdigi tlen, len(text), 3)]
digits.insert(0 , _decoder[text[:firstdigitlen]])
return int(''.join(dig its), 8)

if __name__ == '__main__':
tests = [ (0,'0'), (5,'101'), (15,'1111'), (16,'10000')]

for n,t in tests:
assert t == tobinary(n)
assert n == frombinary(t)
assert n == frombinary('0'+ t)
assert n == frombinary('00' +t)
assert n == frombinary('000 '+t)



-Scott David Daniels
Scott.Daniels@A cm.Org