Author vstinner
Recipients vstinner
Date 2017-12-14.23:11:19
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <1513293080.01.0.213398074469.issue32329@psf.upfronthosting.co.za>
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Content
Python pretends that hash randomization is always enabled, but it's not:

$ PYTHONHASHSEED=0 python3 -c 'import sys; print(sys.flags.hash_randomization)'
1
vstinner@apu$ PYTHONHASHSEED=0 python3 -c 'import sys; print(hash("abc"))'
4596069200710135518
vstinner@apu$ PYTHONHASHSEED=0 python3 -c 'import sys; print(hash("abc"))'
4596069200710135518
vstinner@apu$ PYTHONHASHSEED=0 python3 -c 'import sys; print(hash("abc"))'
4596069200710135518

=> sys.flags.hash_randomization must be zero


Moreover, the -R flag is always ignored, it's not possible to override the PYTHONHASHSEED environment variable:

vstinner@apu$ PYTHONHASHSEED=0 python3 -R -c 'import sys; print(sys.flags.hash_randomization)'
1
vstinner@apu$ PYTHONHASHSEED=0 python3 -R -c 'import sys; print(hash("abc"))'
4596069200710135518
vstinner@apu$ PYTHONHASHSEED=0 python3 -R -c 'import sys; print(hash("abc"))'
4596069200710135518
vstinner@apu$ PYTHONHASHSEED=0 python3 -R -c 'import sys; print(hash("abc"))'
4596069200710135518

I expect that -R enables hash randomization and overrides PYTHONHASHSEED environment variable.

Attached PR fixes these issues and adds an unit test.
History
Date User Action Args
2017-12-14 23:11:20vstinnersetrecipients: + vstinner
2017-12-14 23:11:20vstinnersetmessageid: <1513293080.01.0.213398074469.issue32329@psf.upfronthosting.co.za>
2017-12-14 23:11:19vstinnerlinkissue32329 messages
2017-12-14 23:11:19vstinnercreate