Ascii to binary conversion

[azrael]

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")

 

[John Machin]

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:
.... ai = ord(a)
.... return ''.join('01'[(ai >> x) & 1] for x in xrange(7, -1, -1))
....
BUT ... why are you doing this so much that the speed matters???

 

[azrael]

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.

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:

...    ai = ord(a)
...    return ''.join('01'[(ai >> x) & 1] for x in xrange(7, -1, -1))
...
'11111111'

BUT ... why are you doing this so much that the speed matters???

 

[Mensanator]

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")

In Pthon 2.6 & 3.0 there actually IS a bin() function.

IDLE 2.6b1'0b110001'

But it has that worthless '0b' decorator, but that's
easily dealt with.

bin(ord('1'))[2:]

'110001'

And you won't get leading 0s unless you ask for them.

bin(ord('1'))[2:].zfill(8)

'00110001'

If you have previous Python versions (and even if you
have 2.6), you might consider getting the gmpy module.
It will convert to any base from 2 to 36 and in addition,
provides a nice set of binary manipulation functions
such as popcount (number of 1-bits), scan1 (finds posistion
of first 1-bit), Hamming Distance (number of differing
bits between two numbers), etc.

'49'
'110001'
'00110001'
3
0
4

3

And you probably won't find anything faster than gmpy.

 

[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

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.

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

 

[John Machin]

the speed matters if you plan to exchange about 10 M ascii chars and
don't wont to wait a year for the results.

WHY do you plan to change about 10 M ascii chars into about 90 M
bytes? Who or what is going to consume the output?

 

[Terry Reedy]

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")

Other alternatives in 2.6 (I believe) and 3.0:'111010101'