Ascii to binary conversion

[azrael]

You see, I don't like reading some tutorials. I pick myself a problem
and look for ways to slove it. I am using Python for about 2 years,
but mostly for image processing. As you say, ord is oposite to chr. I
learn by example.

thnx guys, this looks great


On 9 kol, 16:47, Larry Bates <larry.ba... at websafe.com`> wrote:
> azrael wrote:
> > looks nice. is there an oposite function of ord() so I could also
> > bring a binary number also back to ascii.
>
> > the speed matters if you plan to exchange about 10 M ascii chars and
> > don't wont to wait a year for the results. :)
>
> > On 9 kol, 15:39, John Machin <sjmac... at lexicon.net> wrote:
> >> On Aug 9, 11:18 pm, azrael <jura.gro... at gmail.com> wrote:
>
> >>> Hy folks,
> >>> I googled, and searched, and can not bealive that I have not found a
> >>> built in way to convert the easy and elegant python way a function to
> >>> easily convert simple ascii data to binary and back.
> >>> I've written some my own but they were pretty slow using binascii
> >>> linbrary with hexifly and unhexifly functions conbined with a
> >>> lookuptable of binary and hex values.
> >>> Any idea how to easily write a function that recieves a character or
> >>> string and returns a binary number like:
> >>> ascii("1") is converted to bin("00110001")
> >> Here's one way:
>
> >>>>> def a2b(a):
> >> ...    ai = ord(a)
> >> ...    return ''.join('01'[(ai >> x) & 1] for x in xrange(7, -1, -1))
> >> ...
>
> >>>>> a2b('1')
> >> '00110001'
> >>>>> a2b('2')
> >> '00110010'
> >>>>> a2b(chr(0))
> >> '00000000'
> >>>>> a2b(chr(255))
> >> '11111111'
>
> >> BUT ... why are you doing this so much that the speed matters???
>
> Opposite of ord() is chr().  These functions have been available in every
> language I've used for the last 30 years.  I would suggest that you might want
> to spend a little time reading a good Python book and to work through the
> tutorial.  It will be worth your investment of time.
>
> -Larry