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Re: Performance of int/long in Python 3

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On 26 March 2013 00:17, Steven D'Aprano
<steve+comp.lang.python@pearwood.info> wrote:
> On Mon, 25 Mar 2013 16:16:05 -0700, Ethan Furman wrote:
>
[snip]
>> If you're working with
>> numbers, and speed is an issue, you really should be using one of the
>> numeric or scientific packages out there.
>
[snip]
> What I would like to see though is a module where I can import fixed-
> width signed and unsigned integers that behave like in C, complete with
> overflow, for writing code that matches the same behaviour as other
> languages.

Numpy can do this:

>>> import numpy
>>> a = numpy.array([0], numpy.uint32)
>>> a
array([0], dtype=uint32)
>>> a[0] = -1
>>> a
array([4294967295], dtype=uint32)

Unfortunately it doesn't work with numpy "scalars", so to use this
without the index syntax you'd need a wrapper class. Also it uses
Python style floor rounding rather than truncation as in C (actually I
seem to remember discovering that in C this is implementation
defined).

Presumably ctypes has something like this as well.


Oscar

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Re: Performance of int/long in Python 3 Ethan Furman <ethan@stoneleaf.us> - 2013-03-25 16:16 -0700
  Re: Performance of int/long in Python 3 Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-26 00:17 +0000
    Re: Performance of int/long in Python 3 Chris Angelico <rosuav@gmail.com> - 2013-03-26 11:28 +1100
    Re: Performance of int/long in Python 3 Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-03-26 00:49 +0000
    Re: Performance of int/long in Python 3 Roy Smith <roy@panix.com> - 2013-03-25 20:55 -0400
      Re: Performance of int/long in Python 3 Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-26 05:01 +0000
        Re: Performance of int/long in Python 3 Chris Angelico <rosuav@gmail.com> - 2013-03-26 17:12 +1100
        Re: Performance of int/long in Python 3 Roy Smith <roy@panix.com> - 2013-03-26 09:18 -0400

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