Mirror imaging binary numbers

[Hendrik van Rooyen]

"Craig" <craigtw.online at gmail.com> wrote:


> Hi there,
> 
> I'm trying to switch binary numbers around so that the MSB becomes the
> LSB etc.  Is there an easy way of doing this as I can't seem to find
> anything.  If you could help that would be great.  Thanks and good
> luck.

Are these Python ints, or are they "strings of bytes of known length"?
And do you really want to mirror swap the binary bits or just change the 
byte sequence from say big to little endian? 
- i.e. is MSB most significant bit, or byte?

assuming bit, try this:

>>> num = 12345
>>> q,r = divmod(num,2)
>>> q
6172
>>> r
1
>>> l = [r]
>>> while q:
 q,r = divmod(q,2)
 l.append(r)

 
>>> l
[1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1]
>>> ans = 0
>>> for x in l:
 ans = ans * 2 + x

 
>>> ans
9987
>>> 

and Robert is yer aunty...

- Hendrik