JP-3721: Simplify ModelContainer

[emolter]

Helps to resolve JP-3721

Helps to close spacetelescope/jwst:8738

This PR enables the JWST ModelContainer to no longer inherit from DataModel as part of an effort to make ModelContainer's usage narrower and easier to understand.

Tasks

• update or add relevant tests
• update relevant docstrings and / or docs/ page
• Does this PR change any API used downstream? (if not, label with no-changelog-entry-needed)
  • write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see below for change types)
  • run jwst regression tests with this branch installed ("git+https://github.com/<fork>/stdatamodels@<branch>")

news fragment change types...

• changes/<PR#>.feature.rst: new feature
• changes/<PR#>.bugfix.rst: fixes an issue
• changes/<PR#>.doc.rst: documentation change
• changes/<PR#>.removal.rst: deprecation or removal of public API
• changes/<PR#>.misc.rst: infrastructure or miscellaneous change

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 66.55%. Comparing base (fd6be8d) to head (9bcaae1).
Report is 4 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #330   +/-   ##
=======================================
  Coverage   66.55%   66.55%           
=======================================
  Files         102      102           
  Lines        5456     5457    +1     
=======================================
+ Hits         3631     3632    +1     
  Misses       1825     1825           

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[emolter]

started jwst regtests here

[braingram]

This PR enables the JWST ModelContainer to no longer inherit from DataModel and to no longer require its own save method, as part of an effort to make ModelContainer's usage narrower and easier to understand.

I follow the changes motivated by the inheritance change. Since ModelContainer is no longer a JwstDataModel subclass it won't enter:

stdatamodels/src/stdatamodels/jwst/datamodels/util.py

Lines 103 to 105 in 852c8d7

	elif isinstance(init, model_base.JwstDataModel):
	# Copy the object so it knows not to close here
	return init.__class__(init, **kwargs)

by switching list to Sequence here:

stdatamodels/src/stdatamodels/jwst/datamodels/util.py

Lines 156 to 162 in 852c8d7

	elif is_association(init) or isinstance(init, list):
	try:
	from jwst.datamodels import ModelContainer
	except ImportError as err:
	raise ValueError("Cannot open an association without the jwst package installed") from err
	return ModelContainer(init, **kwargs)

dm.open(container) will do the same thing as before (call ModelContainer(container)).

I don't following the no longer require its own save bit. Is that just in reference to AbstractDataModel.save?

[emolter]

I don't following the no longer require its own save bit. Is that just in reference to AbstractDataModel.save?

Yes, and it hasn't got anything to do with stdatamodels specifically, as you correctly point out. I will remove it from the summary

[braingram]

LGTM.

[emolter]

regression tests passed. @braingram I don't have permissions to request additional reviewers nor merge in this repository, feel free to do either at your convenience