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Date: Wed, 22 Jan 2014 11:18:55 -0700
Subject: Re: No overflow in variables?
From: Larry Martell <larry.martell@gmail.com>
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Xref: csiph.com comp.lang.python:64520

On Wed, Jan 22, 2014 at 11:09 AM, Philip Red
<filippo.biolcati@googlemail.com> wrote:
> Hi everyone. First of all sorry if my english is not good.
> I have a question about something in Python I can not explain:
> in every programming language I know (e.g. C#) if you exceed the max-value of a certain type (e.g. a long-integer) you get an overflow. Here is a simple example in C#:
>
>         static void Main(string[] args)
>         {
>             Int64 x = Int64.MaxValue;
>             Console.WriteLine(x);       // output: 9223372036854775807
>             x = x * 2;
>             Console.WriteLine(x);       // output: -2 (overflow)
>             Console.ReadKey();
>         }
>
> Now I do the same with Python:
>
>             x = 9223372036854775807
>             print(type(x))             #   <class 'int'>
>             x = x * 2                  #   18446744073709551614
>             print(x)                   #   <class 'int'>
>             print(type(x))
>
> and I get the right output without overflow and the type is always a 'int'.
> How does Python manages internally the types and their values? Where are they stored?
>
> Thank you for your help :)

This may help you understand:

http://www.python.org/dev/peps/pep-0237/