add flags in the merge tool for the different merge strategies

Author: TjarkMiener

src/ctapipe/tools/merge.py

@@ -82,6 +82,18 @@ class MergeTool(Tool):
     }
 
     flags = {
+        "single-ob": (
+            {"HDF5Merger": {"merge_strategy": "events-single-ob"}},
+            (
+                "By default, the merge tool assumes it is merging multiple"
+                " observation blocks. This option switches to merging multiple"
+                " chunks of events of the same ob."
+            ),
+        ),
+        "attach-monitoring": (
+            {"HDF5Merger": {"merge_strategy": "monitoring-only"}},
+            ("Attach monitoring data from the same observation block."),
+        ),
         "progress": (
             {"MergeTool": {"progress_bar": True}},
             "Show a progress bar for all given input files",

src/ctapipe/tools/tests/test_merge.py

@@ -242,7 +242,7 @@ def test_merge_single_ob(tmp_path, dl1_file, dl1_chunks):
             str(path1),
             str(path2),
             f"--output={output}",
-            "--merge-strategy=events-single-ob",
+            "--single-ob",
         ],
         cwd=tmp_path,
         raises=True,
@@ -268,7 +268,7 @@ def test_merge_single_ob_append(tmp_path, dl1_file, dl1_chunks):
         argv=[
             str(path1),
             f"--output={output}",
-            "--merge-strategy=events-single-ob",
+            "--single-ob",
         ],
         cwd=tmp_path,
         raises=True,
@@ -279,7 +279,7 @@ def test_merge_single_ob_append(tmp_path, dl1_file, dl1_chunks):
         argv=[
             str(path2),
             f"--output={output}",
-            "--merge-strategy=events-single-ob",
+            "--single-ob",
             "--append",
         ],
         cwd=tmp_path,
@@ -308,6 +308,6 @@ def test_merge_exceptions(
             str(dl1_mon_pointing_file),
             "--append",
             "--monitoring",
-            "--merge-strategy=events-single-ob",
+            "--single-ob",
         ]
         run_tool(MergeTool(), argv=argv, cwd=tmp_path)