integer allocation in Python

gistfile1.txt

$ python2.7
Python 2.7.2 (default, Oct 17 2011, 00:04:42) 
[GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> result = None
>>> for n in range(1000):
...     m = int(str(n))
...     previous_result = result
...     result = n is m
...     if result != previous_result:
...         print n, result
... 
0 True
257 False
>>> 
$ python3.3
Python 3.3.1 (default, Sep 15 2013, 10:03:49) 
[GCC 4.2.1 Compatible Apple LLVM 4.2 (clang-425.0.28)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> result = None
>>> for n in range(1000):
...     m = int(str(n))
...     previous_result = result
...     result = n is m
...     if result != previous_result:
...         print(n, result)
... 
0 True
257 False
>>> 

/cc @PawelStiasny