Message8342

Arguably object comparison (using "is") of strings is perhaps expected to be implementation dependant, but this could be viewed as a regression from Jython 2.5:

C Python:

$ python
Python 2.7.5 (default, Aug 25 2013, 00:04:04) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.0.68)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> "a" is "a"
True
>>> quit()

$ pypy2.2
Python 2.7.3 (87aa9de10f9c, Nov 24 2013, 20:57:21)
[PyPy 2.2.1 with GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
And now for something completely different: ``the zen attitude to programming:
reducing the oopses in your life''
>>>> "a" is "a"
True
>>>> quit()

Jython 2.5

$ jython2.5
Jython 2.5.2 (Release_2_5_2:7206, Mar 2 2011, 23:12:06) 
[Java HotSpot(TM) 64-Bit Server VM (Apple Inc.)] on java1.6.0_65
Type "help", "copyright", "credits" or "license" for more information.
>>> "a" is "a"
True
>>> quit()

Jython 2.7 beta 2:

$ jython2.7
"a" Jython 2.7b2 (default:a5bc0032cf79+, Apr 22 2014, 21:20:17) 
[Java HotSpot(TM) 64-Bit Server VM (Oracle Corporation)] on java1.7.0_55
Type "help", "copyright", "credits" or "license" for more information.
>>> "a" is "a"
False
>>> 4 is 4
True
>>> quit()

All tests show above were on Mac OS X.