Fix a bug in how a image group name is determined

CHANGES.rst

@@ -16,7 +16,7 @@ assign_wcs
 associations
 ------------
 
-- Ensure NRS IFU exposures don't make a spec2 association for grating/filter combinations 
+- Ensure NRS IFU exposures don't make a spec2 association for grating/filter combinations
   where the nrs2 detector isn't illuminated.  Remove dupes in mkpool. [#8395]
 
 - Match NIRSpec imprint observations to science exposures on mosaic tile location
@@ -39,7 +39,7 @@ extract_1d
 general
 -------
 
-- Removed deprecated stdatamodels model types ``DrizProductModel``, 
+- Removed deprecated stdatamodels model types ``DrizProductModel``,
   ``MIRIRampModel``, and ``MultiProductModel``. [#8388]
 
 outlier_detection
@@ -79,6 +79,8 @@ tweakreg
 
 - Output source catalog file now respects ``output_dir`` parameter. [#8386]
 
+- Improved how a image group name is determined. [#8426]
+
 
 1.14.0 (2024-03-29)
 ===================
@@ -94,7 +96,7 @@ ami
 - Additional optional input arguments for greater user processing flexibility.
   See documentation for details. [#7862]
 
-- Bad pixel correction applied to data using new NRM reference file to calculate 
+- Bad pixel correction applied to data using new NRM reference file to calculate
   complex visibility support (M. Ireland method implemented by J. Kammerer). [#7862]
 
 - Make ``AmiAnalyze`` and ``AmiNormalize`` output conform to the OIFITS standard. [#7862]
@@ -129,7 +131,7 @@ charge_migration
   as DO_NOT_USE.  This group, and all subsequent groups, are then flagged as
   CHARGELOSS and DO_NOT_USE.  The four nearest pixel neighbor are then flagged
   in the same group. [#8336]
-  
+
 - Added warning handler for expected NaN and inf clipping in the
   ``sigma_clip`` function. [#8320]
 
@@ -415,7 +417,7 @@ tweakreg
 
 - Fixed a bug that caused failures instead of warnings when no GAIA sources
   were found within the bounding box of the input image. [#8334]
-  
+
 - Suppress AstropyUserWarnings regarding NaNs in the input data. [#8320]
 
 wfs_combine

jwst/tweakreg/tests/test_tweakreg.py

@@ -41,20 +41,21 @@ def test_is_wcs_correction_small(offset, is_good):
 @pytest.mark.parametrize(
     "groups, all_group_names, common_name",
     [
-        ([['abc1_cal.fits', 'abc2_cal.fits']], [], ['abc']),
+        ([['abc1_cal.fits', 'abc2_cal.fits']], {}, ['abc #1']),
         (
             [
                 ['abc1_cal.fits', 'abc2_cal.fits'],
                 ['abc1_cal.fits', 'abc2_cal.fits'],
                 ['abc1_cal.fits', 'abc2_cal.fits'],
                 ['def1_cal.fits', 'def2_cal.fits'],
+                ['cba1_cal.fits', 'cba2_cal.fits'],
             ],
-            [],
-            ["abc", "abc1", "abc2", "def"],
+            {'cba': 1},
+            ["abc #1", "abc #2", "abc #3", "def #1", "cba #2"],
         ),
-        ([['cba1_cal.fits', 'abc2_cal.fits']], [], ['Group #1']),
-        ([['cba1_cal.fits', 'abc2_cal.fits']], ['Group #1'], ['Group #2']),
-        ([['cba1_cal.fits', 'abc2_cal.fits']], None, ['Unnamed Group']),
+        ([['cba1_cal.fits', 'abc2_cal.fits']], {}, ['Group #1']),
+        ([['cba1_cal.fits', 'abc2_cal.fits']], {'Group': 1}, ['Group #2']),
+        ([['cba1_cal.fits', 'abc2_cal.fits']], None, ['Group #1']),
     ]
 )
 def test_common_name(groups, all_group_names, common_name):
@@ -69,6 +70,22 @@ def test_common_name(groups, all_group_names, common_name):
         assert cn == cn_truth
 
 
+def test_common_name_special():
+    all_group_names = {}
+    group = []
+    cn = tweakreg_step._common_name(group, all_group_names)
+    assert cn == 'Group #1'
+
+    group = []
+    all_group_names = {'abc': 1, 'abc #2': 1}
+    for fname in ['abc1', 'abc2']:
+        model = ImageModel()
+        model.meta.filename = fname
+        group.append(model)
+    cn = tweakreg_step._common_name(group, all_group_names)
+    assert len(cn.rsplit('_', 1)[1]) == 6
+
+
 def test_expected_failure_bad_starfinder():
 
     model = ImageModel()

jwst/tweakreg/tweakreg_step.py

@@ -5,6 +5,7 @@
 
 """
 from os import path
+import uuid
 
 from astropy.table import Table
 from astropy import units as u
@@ -109,6 +110,7 @@ class TweakRegStep(Step):
     reference_file_types = []
 
     def process(self, input):
+        _common_name.gid = 0
         use_custom_catalogs = self.use_custom_catalogs
 
         if use_custom_catalogs:
@@ -294,8 +296,8 @@ def process(self, input):
         elif len(grp_img) > 1:
             # create a list of WCS-Catalog-Images Info and/or their Groups:
             imcats = []
-            all_group_names = []
-            for g in grp_img:
+            all_group_names = {}
+            for k, g in enumerate(grp_img):
                 if len(g) == 0:
                     raise AssertionError("Logical error in the pipeline code.")
                 else:
@@ -511,7 +513,7 @@ def process(self, input):
                     )
 
         return images
-    
+
 
     def _write_catalog(self, image_model, catalog, filename):
         '''
@@ -614,31 +616,35 @@ def _imodel2wcsim(self, image_model):
 
 
 def _common_name(group, all_group_names=None):
-    file_names = [path.splitext(im.meta.filename)[0].strip('_- ')
-                  for im in group]
+    file_names = [
+        path.splitext(im.meta.filename)[0].strip('_- ') for im in group
+    ]
 
     cn = path.commonprefix(file_names)
 
     if all_group_names is None:
-        if not cn:
-            return 'Unnamed Group'
+        if cn:
+            return cn
+        else:
+            _common_name.gid += 1
+            return f"Group #{_common_name.gid}"
     else:
-        if not cn or cn in all_group_names:
-            # find the smallest group number to make "Group #..." unique
-            max_id = 1
-            if not cn:
-                cn = "Group #"
-            for name in all_group_names:
-                try:
-                    cid = int(name.lstrip(cn))
-                    if cid >= max_id:
-                        max_id = cid + 1
-                except ValueError:
-                    pass
-            cn = f"{cn}{max_id}"
-        all_group_names.append(cn)
-
-    return cn
+        if not cn:
+            cn = "Group"
+
+        grp_no = all_group_names.get(cn, 0) + 1
+        grp_id = f"{cn} #{grp_no}"
+        if grp_id in all_group_names:
+            # just try some shortened uuid until it is unique:
+            while grp_id in all_group_names:
+                grp_id = f"{cn}_{str(uuid.uuid4())[-6:]}"
+            all_group_names[grp_id] = 0
+        else:
+            all_group_names[cn] = grp_no
+        return grp_id
+
+
+_common_name.gid = 0
 
 
 def _parse_catfile(catfile):