maximum length of a list & tuple

[Bengt Richter]

On Mon, 12 Apr 2004 07:22:26 -0400, Peter Hansen <peter at engcorp.com> wrote:

>Peter Hansen wrote:
>
>> Josiah Carlson wrote:
>> 
>>> Checking the memory usage of Python before and after the creation of 1 
>>> million integer list, I get a /very/ consistant ~16 bytes per.  That 
>>> would be 12 bytes for the object, and 4 bytes for each pointer in the 
>>> list.  
>> 
>> Please post the expression you are using, for comparison.
>
>By the way, in case it wasn't clear, we have a disagreement (and perhaps
>a misunderstanding) only about the meaning of the original code posted.
>You believe it is allocating many integers.  I believe it allocates
>only a single one.  Perhaps one of us is wrong.  I hadn't read the code
>in great detail, and still haven't, and perhaps that's my mistake.
>Depending on your reply, I'll actually go back and look at it closely
>and perhaps execute it myself and see the result (in terms of the list
>produced, not in terms of the memory consumption).  Maybe you will
>do the same and we'll identify which of us is mistaken...
>
 >>> dict([(id(x),x) for x in [1]*100])
 {7946208: 1}
 >>> dict([(id(x),x) for x in range(5)])
 {7939088: 0, 7946208: 1, 7943184: 4, 7945200: 2, 7944192: 3}
 >>> dict([(id(x),x) for x in range(5)*10])
 {7939088: 0, 7946208: 1, 7943184: 4, 7945200: 2, 7944192: 3}

 >>> for v in -6,-5,0,1,99,100:
 ...     print dict([(id(x),x) for x in [v  for i in xrange(5)]])
 ...
 {8053508: -6}
 {7936720: -5}
 {7939088: 0}
 {7946208: 1}
 {8042496: 99}
 {8166456: 100}
 >>> for v in -6,-5,0,1,99,100:
 ...     print dict([(id(x),x) for x in [v*1  for i in xrange(5)]])
 ...
 {8166384: -6, 8166444: -6, 8166492: -6, 8166360: -6, 8166468: -6}
 {7936720: -5}
 {7939088: 0}
 {7946208: 1}
 {8042496: 99}
 {8166360: 100, 8166468: 100, 8166480: 100, 8166348: 100, 8166492: 100}

Regards,
Bengt Richter