Surprise using the 'is' operator
tjreedy at udel.edu
Wed Sep 27 19:18:09 CEST 2006
"Georg Brandl" <g.brandl-nospam at gmx.net> wrote in message
news:efe7v1$8ls$1 at news.albasani.net...
> tobiah wrote:
>> Suppose I fill an list with 100 million random integers in the range
>> of 1 - 65535. Wouldn't I save much memory if all of the ocurrances
>> of '12345' pointed to the same integer object? Why should more be made,
>> when they all do the same thing, and are not subject to change?
> Because for typical usage of integers (which doesn't include your
> it is more expensive to check if there's already an integer with that
> value out there than to create a new one.
I am not sure what you are saying. Every (C) int is checked to see if it
is in the preallocated range before making a new Python int object. The
reason for the low limit is the various time-space tradeoffs applied across
the entire range of programs.
Terry Jan Reedy
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