On Sat, Sep 29, 2018 at 7:19 AM Greg Ewing <greg.ew...@canterbury.ac.nz> wrote: > > Chris Angelico wrote: > > It is still fundamentally difficult to make assertions about the file > > system as pre/post contracts. > > When you consider race conditions, I'd say it's impossible. > A postcondition check involving the file system could fail > even if the function does its job perfectly.
I guess that depends on the meaning of "contract". If it means "there is a guarantee that this is true after this function returns", then yes, the race condition means it's impossible. But as a part of the function's declared intent, it's fine to have a postcondition of "the directory will be empty" even though something could drop a file into it. But if it's the latter... contracts are just a different way of defining unit tests.... and we're right back where we started. ChrisA _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
