On 15 Apr 2021, at 12:39 am, Robert Kern <robert.k...@gmail.com> wrote: > > On Wed, Apr 14, 2021 at 6:16 PM Andrew Nelson <andyf...@gmail.com> wrote: > On Thu, 15 Apr 2021 at 07:15, Robert Kern <robert.k...@gmail.com> wrote: > On Wed, Apr 14, 2021 at 4:37 PM Joachim Wuttke <j.wut...@fz-juelich.de> wrote: > Regarding numpy, I'd propose a bolder measure: > To let savetxt(fname, X, ...) store exactly the same information in > compressed and uncompressed files, always invoke gzip with mtime = 0. > > I agree. > > I might look into making a PR for this. To be clear what would the desired > functionality be: > > 1. Mandatory to have mtime = 0? > > 2. Default mtime = 0, but `np.save*` has an extra `mtime` kwd that allows to > set the mtime? > > 3. Default mtime = time.time(), but `np.save*` has an extra `mtime` kwd that > allows to set the mtime = 0? > > > As Joachim says for testing/git-related purposes it is nice to have bit-wise > unchanged files produced (such that the file-hash is unchanged), but I can > also see that it might be nice to have a modification time when files > contained in a zip file were last changed (e.g. write with numpy, > check/inspect with a different module). Of course with the latter you could > just look at the overall file-write date, they should be the same. > > I suspect no one's actually looking at the timestamp inside the file > (relevant XKCD comic[1] notwithstanding). I'd lean towards boldness here and > just set mtime=0. If someone screams, then we can add in the option for them > to get the old functionality. But moving closer to reliably reproducible file > formats is a goal worth changing the default behavior. > I was also a bit worried about that – a) people actively using the timestamp for information and b) files with mtime=0 decompressing to files showing a creation date in 1970 or something. But all the Unix timestamps at least seem to be determined differently, so maybe the benefits do outweigh the risks.
> [1] https://xkcd.com/1172/ :D Derek _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@python.org https://mail.python.org/mailman/listinfo/numpy-discussion
