make {experiment,query}.py classes abstract

python-spec/src/somacore/data.py

@@ -479,6 +479,8 @@ def write(
 
                 Arrow table: a COO table, with columns named ``soma_dim_0``,
                     ..., ``soma_dim_N`` and ``soma_data``.
+            platform_config: platform-specific configuration; keys are SOMA
+                implementation names.
 
         Returns: ``self``, to enable method chaining.
 

python-spec/src/somacore/experiment.py

@@ -1,6 +1,7 @@
+import abc
 from typing import Generic, Optional, TypeVar
 
-from typing_extensions import Final, Self
+from typing_extensions import Final
 
 from . import _mixin
 from . import base
@@ -9,6 +10,7 @@
 from . import measurement
 from . import query
 from . import scene
+from .query import ExperimentAxisQuery
 
 _DF = TypeVar("_DF", bound=data.DataFrame)
 """An implementation of a DataFrame."""
@@ -20,8 +22,10 @@
 """The root SOMA object type of the implementation."""
 
 
-class Experiment(
-    collection.BaseCollection[_RootSO], Generic[_DF, _MeasColl, _SceneColl, _RootSO]
+class Experiment(  # type: ignore[misc]  # __eq__ false positive
+    collection.BaseCollection[_RootSO],
+    Generic[_DF, _MeasColl, _SceneColl, _RootSO],
+    abc.ABC,
 ):
     """A collection subtype representing an annotated 2D matrix of measurements.
 
@@ -33,22 +37,6 @@ class Experiment(
     Lifecycle: maturing
     """
 
-    # This class is implemented as a mixin to be used with SOMA classes.
-    # For example, a SOMA implementation would look like this:
-    #
-    #     # This type-ignore comment will always be needed due to limitations
-    #     # of type annotations; it is (currently) expected.
-    #     class Experiment(  # type: ignore[type-var]
-    #         ImplBaseCollection[ImplSOMAObject],
-    #         somacore.Experiment[
-    #             ImplDataFrame,    # _DF
-    #             ImplMeasurement,  # _MeasColl
-    #             ImplScene,        # _SceneColl
-    #             ImplSOMAObject,   # _RootSO
-    #         ],
-    #     ):
-    #         ...
-
     __slots__ = ()
     soma_type: Final = "SOMAExperiment"  # type: ignore[misc]
 
@@ -83,18 +71,11 @@ def axis_query(
         *,
         obs_query: Optional[query.AxisQuery] = None,
         var_query: Optional[query.AxisQuery] = None,
-    ) -> "query.ExperimentAxisQuery[Self]":
+    ) -> ExperimentAxisQuery:
         """Creates an axis query over this experiment.
 
         See :class:`query.ExperimentAxisQuery` for details on usage.
 
         Lifecycle: maturing
         """
-        # mypy doesn't quite understand descriptors so it issues a spurious
-        # error here.
-        return query.ExperimentAxisQuery(  # type: ignore[type-var]
-            self,
-            measurement_name,
-            obs_query=obs_query or query.AxisQuery(),
-            var_query=var_query or query.AxisQuery(),
-        )
+        raise NotImplementedError

python-spec/src/somacore/query/__init__.py

@@ -3,10 +3,12 @@
 
 ExperimentAxisQuery = query.ExperimentAxisQuery
 AxisColumnNames = query.AxisColumnNames
+AxisIndexer = query.AxisIndexer
 AxisQuery = axis.AxisQuery
 
 __all__ = (
     "ExperimentAxisQuery",
     "AxisColumnNames",
+    "AxisIndexer",
     "AxisQuery",
 )