# Ascii to binary conversion

Larry Bates larry.bates at websafe.com`
Sat Aug 9 16:47:53 CEST 2008

```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

```