Irmen de Jong
irmen.NOSPAM at xs4all.nl
Mon Apr 5 08:45:19 EDT 2010
On 5-4-2010 13:48, superpollo wrote:
> Jason Friedman ha scritto:
>> I saw this posted in the July issue but did not see any follow-up there:
>> $ python
>> Python 2.6.4 (r264:75706, Dec 7 2009, 18:43:55)
>> [GCC 4.4.1] on linux2
>> Type "help", "copyright", "credits" or "license" for more information.
>>>>> a = 500
>>>>> b = 500
>>>>> a == b
>>>>> a is b
>>>>> p = 50
>>>>> q = 50
>>>>> p == q
>>>>> p is q
I fail to see the fun?
Remember that everything in Python is an object, even integers.
For integers, I believe Python creates the first 100 integer objects and reuses them.
Larger integers are created when needed, and are different objects.
The example also shows why it usually is wrong to use object comparison ('is') when you
really mean equality (==).
More information about the Python-list