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

Groups > comp.lang.python > #86253

Re: list storing variables

Show all headers | View raw

Marko Rauhamaa wrote:

> Peter Pearson <pkpearson@nowhere.invalid>:
> 
>>>>>> a = 2; b = 5
>>>>>> Li = [a, b]
>>>>>> Li
>>> [2, 5]
>>>>>> a=3
>>>>>> Li
>>> [2, 5]
>>
>> [...]
>>
>> The word "variable" brings implications and assumptions that get
>> people into trouble in Python.  Python doesn't have variables.
>> It has objects, and you can assign names to objects -- like sticky
>> notes, as someone in this newsgroup helpfully pointed out long ago.
>>
>> This way of thinking is significantly different from the familiar
>> "variable" mind-set of C, but looks similar enough to produce some
>> confusion.  For me, the sticky-note analogy helped a lot, and in a
>> few days many things made more sense.
> 
> It's no different in C:
> 
>    #include <stdio.h>
> 
>    int main()
>    {
>       int a = 2, b = 5;
>       int Li[2] = { a, b };
>       printf("%d %d\n", Li[0], Li[1]);
>       a = 3;
>       printf("%d %d\n", Li[0], Li[1]);
>       return 0;
>    }
> 
> Outputs:
> 
>    2 5
>    2 5
> 
> 
> Marko

The OP explicitly mentions the & operator. There's no python analog to that 
and the behavior shown below:

$ cat pointers.c
#include <stdio.h>

int main()
{
  int a = 2, b = 5;
  int * Li[2] = { &a, &b };
  printf("%d %d\n", *Li[0], *Li[1]);
  a = 3;
  printf("%d %d\n", *Li[0], *Li[1]);
  return 0;
}
$ gcc pointers.c
$ ./a.out 
2 5
3 5

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

Thread

list storing variables "ast" <nomail@invalid.com> - 2015-02-23 13:55 +0100
  Re: list storing variables Dave Angel <davea@davea.name> - 2015-02-23 08:24 -0500
  Re: list storing variables Marko Rauhamaa <marko@pacujo.net> - 2015-02-23 15:49 +0200
  Re: list storing variables Peter Pearson <pkpearson@nowhere.invalid> - 2015-02-23 17:35 +0000
    Re: list storing variables Marko Rauhamaa <marko@pacujo.net> - 2015-02-23 20:22 +0200
      Re: list storing variables Peter Otten <__peter__@web.de> - 2015-02-23 19:41 +0100
        Re: list storing variables Marko Rauhamaa <marko@pacujo.net> - 2015-02-23 21:06 +0200
          Re: list storing variables Chris Angelico <rosuav@gmail.com> - 2015-02-24 06:17 +1100
            Re: list storing variables Marko Rauhamaa <marko@pacujo.net> - 2015-02-23 22:25 +0200
          Re: list storing variables Ian Kelly <ian.g.kelly@gmail.com> - 2015-02-23 12:29 -0700
            Re: list storing variables Marko Rauhamaa <marko@pacujo.net> - 2015-02-23 22:38 +0200
  Re: list storing variables Ben Finney <ben+python@benfinney.id.au> - 2015-02-24 09:03 +1100
    Re: list storing variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-02-24 13:24 +1100
      Re: list storing variables Marko Rauhamaa <marko@pacujo.net> - 2015-02-24 10:18 +0200

csiph-web