Performance of int/long in Python 3

Steven D'Aprano steve+comp.lang.python at
Tue Mar 26 01:17:04 CET 2013

On Mon, 25 Mar 2013 16:16:05 -0700, Ethan Furman wrote:

> On 03/25/2013 02:51 PM, Chris Angelico wrote:
>> Python 3's int is faster than Python 2's long, but slower than Python
>> 2's int. So the question really is, would a two-form representation be
>> beneficial, and if so, is it worth the coding trouble?
> I'm inclined to say it's not worth the trouble.  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.

Or PyPy, which will probably optimize it just fine.

Also, speaking as somebody who remembers a time when ints where not 
automatically promoted to longs (introduced in, Python 2.2, I think?) let 
me say that having a single unified int type is *fantastic*, and managing 
ints/longs by hand is a right royal PITA.

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 


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