Update to Python=3.9 and update Django

[jonwzheng]

This PR seeks to update RMG-website to be compatible with Python 3.9 so that it can leverage the newest version of RMG-Py and other packages.

To do this, a number of things need to be updated simultaneously (avoid dependency hell):

• Either update solprop using the py3.9 compatible version, or turn it into an API service so that it can be queried separately. Updating solprop would for now be the most straightforward option. Although an API service would be the best solution technologically, it would take the most technical load to learn and implement sustainably. Another way is to call it via a subprocess in its own separate conda or docker environment, which would also require some rewriting of the backend. Key concern is whether it's fast enough. In the future, probably we want to move toward one of the two latter options, especially if we want to deploy more ML models on the site.
• Update Django from 2.2 and then see what breaks; then fix those errors in the codebase.
• See if any new package versions break existing code

There's also an opportunity to make the conda environment leaner (which should make solving for it more straightforward in general).

edit 23 March 2026 by @JacksonBurns:

@jonwzheng and I have collaboratively made efforts to move solprop into a container and use it as a microservice. This allows us to remain on the old Python 3.7 version and appreciably simplify the RMG-website environment.

[jonwzheng]

Roel has very kindly released a binary of solprop that is compatible with this environment, so we can proceed with using that for now.

[jonwzheng]

To-fix:

• SoluteML not working
• 'ifequal', expected 'endblock' in html rendering of thermo+kinetic database entries.
• get_solvation_data_temp_dep too many values to unpack (expected 2)
• Solubility models: Need to refactor to work with SolubilityData. Also the trained logS model is not present, so the binary doesn't work.
• Test tools
  • NOT NULL constraint failed: rmg_fluxdiagram.java for Generate Flux Diagram. Make migration.
    • The Java error was fixed. There's a circular import problem that's simultaneously resolved in RMG-Py Update Jupyter notebooks and associated codebase [RMG-Py] RMG-Py#2815
  • Populate Reactions has some error with chemkin
    • somehow fixed after making migrations
• Test P-dep network
• Try graphviz again
• Django3.2
  • Update django.db.models.AutoField wherever it appears. I think fixed in migration?
• Environment
  • Pin to django=4.2

[jonwzheng]

Unrelated note, but the entryEdit functionality seems kind of suspicious and maybe we shouldn't allow users to actually use those (I don't think anyone is, and they don't even work on the main site.) We may want to just remove it.

[jonwzheng]

Some Solute (tdep, soluteML) functionalities may be present in SolProp and thereby maybe we don't need chemprop_solvation.

[jonwzheng]

This will almost be ready. It looks like the new environment is working fine now.
Just need to update any code that was broken by these changes, and should be all set...

[jonwzheng]

This PR is now ready for review. If you want to toy around with it, it's active on the dev site: https://rmg.mit.edu:888/

There's a quirk to the installation process. Sometimes a pip version of chemprop_solvation=0.0.2 gets installed somewhere, but that version is broken so it needs to be uninstalled via pip during the install process. please do feel free to test it on your local devices if you want to test it out.

Please let me know if you have any questions or want to chat about any of this

[BonhyeokKoo]

I've confirmed that SoluteML is returning unphysical values in the current development version. This is the same issue described in fhvermei/chemprop_solvation#3, caused by changes in newer descriptastorus versions.

What issues did keeping the older pin of descriptastorus cause?

[jonwzheng]

Old versions of descriptastorus use scipy.gilbrat which was deprecated in scipy 1.9.0 and removed entirely in 1.11.0 because it is a typo: https://docs.scipy.org/doc/scipy-1.10.1/reference/generated/scipy.stats.gilbrat.html

This renders the website inoperable. So we need to use a more recent version of descriptastorus. Maybe 2.5.1 will work? I'll give it a try...

[jonwzheng]

Another option could be to not use chemprop_solvation at all and just use solprop_ml which I think has a re-trained version of SoluteML: https://anaconda.org/simonabuzzi/solprop_ml_mix

This would require some changes to the code though.

[jonwzheng]

Testing other versions of descriptastorus, none of them are compatible:

• 2.0.6 and earlier have the same scipy problem
• Later versions have some other packaging issues.

I see we can get descripastorus=2.5.0 by pinning the scipy version (which isn't a tenable long-term solution, but the env can at least be solved.)

Unfortunately, it looks like this still results in non-physical answers. Even trying descriptastorus=2.2.0 results in the non-physicality. So maybe it's something else?

[JacksonBurns]

@jonwzheng I've completed moving solprop into a microservice. One can now run this alongside RMG-website without needing both installed in the same environment. Latency should be minimal relative to the execution time of solprop itself.

[jonwzheng]

Just fixed a bug in SoluteML. Will try hosting it on the dev site now to test it before production....

[jonwzheng]

Dev website looks like it's working well with the new changes!

[JacksonBurns]

From what (little) I know about web dev, this looks good. The proof is in the pudding, and the pudding runs smoothly and more securely than ever before.

Going to talk on one last commit to update a missing link in the microservice documentation, then you can merge this at your pleasure @jonwzheng. Thanks again for sticking around to help push this over the finish line

[jonwzheng]

I also approve of the microservice solprop changes.