Select an app version#

Goal#

Call a specific version of a PlayMolecule app, instead of the latest-by-default.

Minimal example#

from playmolecule.apps import proteinprepare

# Always whatever version is installed as latest
ed = proteinprepare(outdir="out", pdbid="3ptb")

# Pinned to v1
ed = proteinprepare.v1.proteinprepare(outdir="out", pdbid="3ptb")

Why#

The unqualified app symbol (proteinprepare) is an alias for the latest installed version. That’s convenient for exploration, but it means an update_apps() call can change your script’s behavior without your code changing. For anything reproducible — published results, CI pipelines, batch sweeps — call the version explicitly.

How versions are exposed#

When PlayMolecule discovers an app, it builds a submodule per version:

playmolecule.apps.<appname>             # alias for latest
playmolecule.apps.<appname>.v1          # explicit version 1
playmolecule.apps.<appname>.v2          # explicit version 2
...

Each version submodule exposes the same set of callable functions plus artifacts, datasets, files, and __manifest__. The tests namespace lives on each function (e.g. proteinprepare.v1.proteinprepare.tests), not on the submodule itself. Parameters and defaults can differ between versions — that’s the whole point of versioning.

List versions installed#

import playmolecule.apps.proteinprepare as pp
[name for name in dir(pp) if name.startswith("v") and name[1:].isdigit()]

Or look at the qualified paths in describe_apps():

ProteinPrepare playmolecule.apps.proteinprepare.v1.proteinprepare
ProteinPrepare playmolecule.apps.proteinprepare.v2.proteinprepare

Compare versions before upgrading#

help(proteinprepare.v1.proteinprepare)
help(proteinprepare.v2.proteinprepare)

Each version’s function carries its own manifest-derived docstring, so help shows you exactly what differs between them — useful before an upgrade.

Gotchas#

  • The “latest” alias is computed at import time by natural sort of version strings. v10 correctly sorts after v9.

  • Pinning to a version that isn’t installed raises AttributeError. Catch it explicitly if your script must run against installs of unknown vintage.

  • Pinning a version doesn’t pin the container image’s runtime dependencies, only the manifest contract. Image SHAs change when Acellera ships fixes; combine version pinning with update_apps() discipline for full reproducibility.

See also#