Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #32159

Re: bit count or bit set && Python3

Show all headers | View raw

On 10/25/2012 12:13 PM, rusi wrote:
> On Oct 25, 7:56 pm, Charles Hixson <charleshi...@earthlink.net> wrote:
>> In Python3 is there any good way to count the number of on bits in an
>> integer (after an & operation)?
>> Alternatively, is there any VERY light-weight implementation of a bit
>> set?  I'd prefer to use integers, as I'm probably going to need
>> thousands of these, if the tests work out.  But before I can test, I
>> need a decent bit counter.  (shift, xor, &, and | are already present
>> for integer values, but I also need to count the number of "true" items
>> after the logical operation.  So if a bitset is the correct approach,
>> I'll need it to implement those operations, or their equivalents in
>> terms of union and intersection.)
>>
>> Or do I need to drop into C for this?

If I wanted 1000s of fast limited-length bitsets, I would consider using 
Cython to make an extension class.

-- 
Terry Jan Reedy

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

bit count or bit set && Python3 Charles Hixson <charleshixsn@earthlink.net> - 2012-10-25 07:47 -0700
  Re: bit count or bit set && Python3 rusi <rustompmody@gmail.com> - 2012-10-25 09:13 -0700
    Re: bit count or bit set && Python3 Terry Reedy <tjreedy@udel.edu> - 2012-10-25 16:16 -0400
  Re: bit count or bit set && Python3 Christian Gollwitzer <auriocus@gmx.de> - 2012-10-25 19:25 +0200
    Re: bit count or bit set && Python3 Ian Kelly <ian.g.kelly@gmail.com> - 2012-10-25 12:19 -0600
  Re: bit count or bit set && Python3 casevh@gmail.com - 2012-10-26 08:42 -0700
    Re: bit count or bit set && Python3 Charles Hixson <charleshixsn@earthlink.net> - 2012-10-26 09:30 -0700
  Re: bit count or bit set && Python3 casevh@gmail.com - 2012-10-26 08:42 -0700

csiph-web