Fix naming when adding multiple groups incrementally.

src/dials/util/table_as_hdf5_file.py

@@ -72,11 +72,12 @@ def encode(
         else:
             group = top_group.create_group(second_level_name, track_order=True)
 
-        for i, table in enumerate(reflections):
+        for table in reflections:
             # Allow storing either a single experiment or multi-experiment table.
             # Therefore use a generic 'group' name to avoid any reliance on this name
-            name = f"group_{i}"
-            this_group = group.create_group(name)
+            # name as group_0, group_1 etc.
+            n = len(group)
+            this_group = group.create_group(f"group_{n}")
 
             # Experiment identifiers and ids are required as part of our spec for this format.
             identifier_map = dict(table.experiment_identifiers())

tests/util/test_table_as_hdf5_file.py

@@ -34,8 +34,8 @@ def simple_test_equal(t1, t2):
 
     data = h5py.File(tmp_path / "scaled2.refl", "r")
     # try reading the two experiments to check it was written as h5
-    dset0 = data["dials"]["processing"]["0"]
-    dset1 = data["dials"]["processing"]["1"]
+    dset0 = data["dials"]["processing"]["group_0"]
+    dset1 = data["dials"]["processing"]["group_1"]
     assert dset0["intensity.sum.value"].shape == (4417,)
     assert dset1["intensity.sum.value"].shape == (5555,)
 
@@ -46,8 +46,8 @@ def simple_test_equal(t1, t2):
 
     data = h5py.File(tmp_path / "scaled3.refl", "r")
     # try reading the two experiments to check it was written as h5
-    dset0 = data["dials"]["processing"]["0"]
-    dset1 = data["dials"]["processing"]["1"]
+    dset0 = data["dials"]["processing"]["group_0"]
+    dset1 = data["dials"]["processing"]["group_1"]
     assert dset0["intensity.sum.value"].shape == (4417,)
     assert dset1["intensity.sum.value"].shape == (5555,)