DM-47768: Add "--chains NO-CHILDREN" to query-collections

doc/changes/DM-47768.feature.md

@@ -0,0 +1,2 @@
+Added a `--chains NO-CHILDREN` mode to the `butler query-collections` CLI,
+which returns results without recursing into `CHAINED` collections.

python/lsst/daf/butler/cli/cmd/commands.py

@@ -394,28 +394,33 @@ def prune_datasets(**kwargs: Any) -> None:
     default="TREE",
     help="""Affects how results are presented:
 
-        TABLE lists each dataset in table form, with columns for dataset name
-        and type, and a column that lists children of CHAINED datasets (if any
-        CHAINED datasets are found).
+        TABLE lists each collection in table form, with columns for collection
+        name and type, and a column that lists children of CHAINED collections
+        (if any CHAINED collections are found).
 
         INVERSE-TABLE is like TABLE but instead of a column listing CHAINED
-        dataset children, it lists the parents of the dataset if it is contained
-        in any CHAINED collections.
+        collection children, it lists the parents of the collection if it is
+        contained in any CHAINED collections.
 
-        TREE recursively lists children below each CHAINED dataset in tree form.
+        TREE recursively lists children below each CHAINED collection in tree
+        form.
 
-        INVERSE-TREE recursively lists parent datasets below each dataset in
-        tree form.
+        INVERSE-TREE recursively lists parent collections below each collection
+        in tree form.
 
-        FLATTEN lists all datasets, including child datasets, in one list.
+        FLATTEN lists all collections, including children of CHAINED
+        collections, in one list.
+
+        NO-CHILDREN lists all collections in one list.  CHAINED collections are
+        included, but they are not expanded to include their children.
 
         [default: TREE]""",
     # above, the default value is included, instead of using show_default, so
     # that the default is printed on its own line instead of coming right after
     # the FLATTEN text.
     callback=to_upper,
     type=click.Choice(
-        choices=("TABLE", "INVERSE-TABLE", "TREE", "INVERSE-TREE", "FLATTEN"),
+        choices=("TABLE", "INVERSE-TABLE", "TREE", "INVERSE-TREE", "FLATTEN", "NO-CHILDREN"),
         case_sensitive=False,
     ),
 )

python/lsst/daf/butler/script/queryCollections.py

@@ -28,6 +28,7 @@
 from __future__ import annotations
 
 from collections.abc import Iterable
+from typing import Literal
 
 from astropy.table import Table
 
@@ -166,15 +167,16 @@ def addCollection(info: CollectionInfo, level: int = 0) -> None:
     return table
 
 
-def _getFlatten(
-    repo: str,
-    glob: Iterable[str],
-    collection_type: Iterable[CollectionType],
+def _getList(
+    repo: str, glob: Iterable[str], collection_type: Iterable[CollectionType], flatten_chains: bool
 ) -> Table:
+    """Return collection results as a table representing a flat list of
+    collections.
+    """
     butler = Butler.from_config(repo)
     collections = list(
         butler.collections.query_info(
-            glob or "*", collection_types=frozenset(collection_type), flatten_chains=True
+            glob or "*", collection_types=frozenset(collection_type), flatten_chains=flatten_chains
         )
     )
     names = [c.name for c in collections]
@@ -186,7 +188,7 @@ def queryCollections(
     repo: str,
     glob: Iterable[str],
     collection_type: Iterable[CollectionType],
-    chains: str,
+    chains: Literal["INVERSE-TABLE", "TABLE", "TREE", "INVERSE-TREE", "FLATTEN", "NO-CHILDREN"],
 ) -> Table:
     """Get the collections whose names match an expression.
 
@@ -202,7 +204,6 @@ def queryCollections(
             optional
         If provided, only return collections of these types.
     chains : `str`
-        Must be one of "FLATTEN", "TABLE", or "TREE" (case sensitive).
         Affects contents and formatting of results, see
         ``cli.commands.query_collections``.
 
@@ -215,6 +216,7 @@ def queryCollections(
         return _getTable(repo, glob, collection_type, inverse)
     elif (inverse := chains == "INVERSE-TREE") or chains == "TREE":
         return _getTree(repo, glob, collection_type, inverse)
-    elif chains == "FLATTEN":
-        return _getFlatten(repo, glob, collection_type)
+    elif chains == "FLATTEN" or chains == "NO-CHILDREN":
+        flatten = chains == "FLATTEN"
+        return _getList(repo, glob, collection_type, flatten)
     raise RuntimeError(f"Value for --chains not recognized: {chains}")

tests/test_cliCmdQueryCollections.py

@@ -277,6 +277,24 @@ def testChained(self):
             )
             self.assertAstropyTablesEqual(readTable(result.output), expected, unorderedRows=True)
 
+            result = self.runner.invoke(cli, ["query-collections", "here", "--chains", "NO-CHILDREN"])
+            self.assertEqual(result.exit_code, 0, clickResultMsg(result))
+            expected = Table(
+                array(
+                    (
+                        ("calibration1", "CALIBRATION"),
+                        ("chain1", "CHAINED"),
+                        ("chain2", "CHAINED"),
+                        ("imported_g", "RUN"),
+                        ("imported_r", "RUN"),
+                        ("run1", "RUN"),
+                        ("tag1", "TAGGED"),
+                    )
+                ),
+                names=("Name", "Type"),
+            )
+            self.assertAstropyTablesEqual(readTable(result.output), expected, unorderedRows=True)
+
             # Add a couple more run collections for chain testing
             registry1.registerRun("run2")
             registry1.registerRun("run3")