stio.get_latest_file does not return newest file.

[jluastro]

Description

If my cdbs/mtab/ directory has multiple *tmg.fits files, the old Pysynphot behavior was to take the newest file. This no longer occurs in stsynphot. I tracked it down to an issue in:

stio.get_latest_file('/Users/jlu/work/models/cdbs/mtab/*tmg.fits')

which returns the last file, not the newest file. One would need to sort on the file date to make this work correctly.

Overall, I fixed the issue by deleting older tmg files. This is fine; but there are no instructions for this.

Steps to Reproduce

You will need to have multiple *tmg.fits files.

System Details

macOS-14.2.1-arm64-arm-64bit
Python 3.12.13 | packaged by conda-forge | (main, Mar 5 2026, 17:06:14) [Clang 19.1.7 ]
Numpy 2.4.3
astropy 7.2.0
Scipy 1.17.1
Matplotlib 3.10.8
Synphot 1.7.0
STSynphot

[pllim]

Hi. Thanks for reporting this. Yes, I think the simple sort does not account for the alphanumeric order to circle back around. Recently something was done on the filenaming scheme to account for the fact that Hubble is still in orbit after 36 years. 😅

So how do you determine locally that a file is latest? Creation date? Last modified date?

[pllim]

Also I think it has not been a problem internally at STScI because the data provider moves the older files to "OLD_FILES" sub-directory (e.g., https://ssb.stsci.edu/cdbs/mtab/ ).

So, can you also please give an example of what your local mtab directory looks like so I can reproduce your problem? Thanks!

[jluastro]

Pysynphot must have been working with Last Modified Date for it to work on my system. But that is a good question. Do the TMG files have meta data with the creation date in them? Cheers, Jessica

On Apr 27, 2026, at 8:49 AM, P. L. Lim ***@***.***> wrote: pllim left a comment (spacetelescope/stsynphot_refactor#225) <#225 (comment)> Hi. Thanks for reporting this. Yes, I think the simple sort does not account for the alphanumeric order to circle back around. Recently something was done on the filenaming scheme to account for the fact that Hubble is still in orbit after 36 years. 😅 So how do you determine locally that a file is latest? Creation date? Last modified date? — Reply to this email directly, view it on GitHub <#225 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AALEJQABKEZ2ZWD4CA6OYHL4X56QXAVCNFSM6AAAAACYHX4B6GVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DGMRYGQYDSMRVGY>. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you authored the thread.

======================================== Jessica Lu Chair, Astronomy Department Associate Professor, Astronomy University of California, Berkeley ***@***.*** ========================================

[pllim]

What pysynphot version are you using? As far as I can see, it does the same thing as stsynphot

https://github.com/spacetelescope/pysynphot/blob/a5e76c398f5b03192fa54659f81e7e1a929d9f7c/pysynphot/locations.py#L295

[pllim]

Do the TMG files have meta data with the creation date in them?

Please check USEAFTER value in Primary header. Does that sort properly for you?

[pllim]

Here is more from data curation team:

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Alternatively, if the user has the crds package installed, they can run the get_synphot command. It will download all of the active synphot files, but they will easily get the latest TMC, TMG, and TMT files placed in the mtab directory that’s downloaded. They would first need to create an empty synphot directory (e.g., “synphot_dir”), then run:

crds get_synphot  synphot_dir  hst-edit

where “hst-edit” tells CRDS to use the edit (latest) context to grab the files. Full CRDS package documentation here.

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That said, synphot existed before CRDS, and I am hesitant to recommend CRDS as the primary data retrieval method due to the extra overhead and learning barrier. But if this works better for you, then by all means, use it.