> > Me: For non-singleton immutables, identity is not really a meaningful > thing. I mean, other than in a debugger or code profiler, or something > special like that. I honestly do not know whether, e.g. '(1, "a", 3.5) is > (1, "a", 3.5)'. I'll go try it, but I won't be sure the answer for every > implementation, version, and even runtime, whether that answer will be > consistent. >
So I did try it. I did not necessarily expect these particular results. Moreover, I have a hunch that with PyPy JIT, something similar might actually give different answers at different points when the same line was encountered in a running interpreter. Not this example, but something else that might cache values only later. I haven't done anything sneaky with the version at those paths. They are all what the environment name hints they should be. PyPy is at 3.6, which is the latest version on conda-forge. 810-tmp % $HOME/miniconda3/envs/py2.7/bin/python -c 'print((1, "a", 3.5) is (1, "a", 3.5))' False 811-tmp % $HOME/miniconda3/envs/py3.4/bin/python -c 'print((1, "a", 3.5) is (1, "a", 3.5))' False 812-tmp % $HOME/miniconda3/envs/py3.8/bin/python -c 'print((1, "a", 3.5) is (1, "a", 3.5))' <string>:1: SyntaxWarning: "is" with a literal. Did you mean "=="? True 813-tmp % $HOME/miniconda3/envs/pypy/bin/python -c 'print((1, "a", 3.5) is (1, "a", 3.5))' True 814-tmp % $HOME/miniconda3/envs/py1/bin/python -c 'print (1, "a", 3.5) is (1, "a", 3.5)' 0 -- The dead increasingly dominate and strangle both the living and the not-yet born. Vampiric capital and undead corporate persons abuse the lives and control the thoughts of homo faber. Ideas, once born, become abortifacients against new conceptions.
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