On Wed, Sep 15, 2021 at 9:36 AM Cameron Simpson <c...@cskk.id.au> wrote: > > On 15Sep2021 07:50, Chris Angelico <ros...@gmail.com> wrote: > >On Wed, Sep 15, 2021 at 7:43 AM Cameron Simpson <c...@cskk.id.au> wrote: > >> I know I'm atypical, but I have quite a lot of multithreaded stuff, > >> including command line code. So while it'd be ok to avoid this context > >> manager for my own code, I fear library modules, either stdlib or pypi, > >> quietly using this in their code, making them unuseable in the general > >> case. Unrepairably unuseable, for the user. > > > >Library code shouldn't be changing the working directory, context > >manager or not. That belongs to the application. > > Entirely agree. > > I'm concerned that convenient stackable chdir is a bug magnet, and would > creep into library code. Maybe not in the stdlib, but there's no point > writing such a context manager if it isn't goingg to be used, and > therefore it could get used in library code. Imagine when a popular pypi > module starts using it internally and breaks a multithreaded app > previously relying on it? > > >> I think what would be more useful is a context manager which worked on a > >> threading.local which pushed/popped a reference directory path, and had > >> an open() method which used that (and friends for other pathname based > >> functions). > > > >Hmm. If it's going to push/pop directories, it should probably work > >with file descriptors rather than path names, and effectively turn all > >open calls into openat calls. > > Yah. I even thought about that during my sketch. But (a) I've possibly > never used openat() so I'm unfamiliar with it (other than its existence) > and (b) I don't think that many other OS calls accept a file descriptor. > Which still leaves one with the os.path.join() approach, and a mix might > be inconsistent. >
I believe that, at the OS level, there are *at() versions of everything relevant. But the question is more whether it would work at the Python level. For instance, you can use os.open() with a dir_fd parameter, but I don't think there's a good way to make the builtin open() use a reference directory. Making that happen would probably be a good thing, but a decidedly nontrivial change. ChrisA _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/NPZC52I3V3Q4JMBAY3NFXIPWCEZX4DVJ/ Code of Conduct: http://python.org/psf/codeofconduct/
