Fix to issue #2103 - failed to parse lists with tuples in detnum

pypeit/par/util.py

@@ -4,6 +4,7 @@
 
 .. include:: ../include/links.rst
 """
+import ast
 
 from configobj import ConfigObj
 from IPython import embed
@@ -59,17 +60,40 @@ def recursive_dict_evaluate(d):
             continue
 
         if isinstance(d[k], list) and any(['(' in e for e in d[k]]):
-            # NOTE: This enables syntax for constructing one or more tuples.
+            # NOTE: This enables syntax for constructing one or more tuples,
+            # including mixed lists of plain values and tuples (e.g.,
+            # "detnum = 1,(2,6)").
+            #
+            # First, try reconstructing the full expression and evaluating it
+            # with ast.literal_eval.  This correctly handles mixed cases like
+            # "1,(2,6)" that _eval_iter cannot parse.
+            reconstructed = ','.join(d[k])
             try:
-                d[k] = utils.eval_tuple(d[k])
-            except (PypeItError, SyntaxError) as e:
-                # The tuple evaluation failed.  Assume that this can be handled
-                # later in the code and leave the dictionary element unaltered.
-                # 
-                # SyntaxError is raised for entries that include a tuple for the
-                # mosaic and a series of locations in the mosaiced image, like
-                # add_slits, rm_slits, and manual.
-                pass
+                result = ast.literal_eval(reconstructed)
+                if isinstance(result, tuple):
+                    if any(isinstance(x, tuple) for x in result):
+                        # Nested tuples or mixed: e.g., "(1,5),(2,6)" or
+                        # "1,(2,6)"
+                        d[k] = list(result)
+                    else:
+                        # Single tuple: e.g., "(2,6)" → wrap in a list
+                        d[k] = [result]
+                else:
+                    d[k] = result
+            except (ValueError, SyntaxError):
+                # ast.literal_eval failed; fall back to the legacy eval_tuple
+                # approach.
+                try:
+                    d[k] = utils.eval_tuple(d[k])
+                except (PypeItError, SyntaxError):
+                    # The tuple evaluation also failed.  Assume that this can
+                    # be handled later in the code and leave the dictionary
+                    # element unaltered.
+                    #
+                    # SyntaxError is raised for entries that include a tuple
+                    # for the mosaic and a series of locations in the mosaiced
+                    # image, like add_slits, rm_slits, and manual.
+                    pass
             continue
 
         if isinstance(d[k], list):

pypeit/tests/test_pypeitpar.py

@@ -6,12 +6,47 @@
 from IPython import embed
 
 import pytest
+from configobj import ConfigObj
 
 from pypeit.par import pypeitpar
 from pypeit.par import parset
+from pypeit.par import util
 from pypeit.spectrographs.util import load_spectrograph
 
 
+def test_detnum_mixed_tuple():
+    """Test parsing of detnum with mixed int and tuple values."""
+
+    # Mixed int and tuple
+    cfg = ConfigObj(['[rdx]', 'detnum = 1,(2,6)'])
+    result = util.recursive_dict_evaluate(dict(cfg))
+    assert result['rdx']['detnum'] == [1, (2, 6)]
+
+    # Single tuple
+    cfg = ConfigObj(['[rdx]', 'detnum = (2,6)'])
+    result = util.recursive_dict_evaluate(dict(cfg))
+    assert result['rdx']['detnum'] == [(2, 6)]
+
+    # Plain list of ints
+    cfg = ConfigObj(['[rdx]', 'detnum = 1,2,3'])
+    result = util.recursive_dict_evaluate(dict(cfg))
+    assert result['rdx']['detnum'] == [1, 2, 3]
+
+    # Multiple tuples (DEIMOS style)
+    cfg = ConfigObj(['[rdx]', 'detnum = (1,5),(2,6),(3,7),(4,8)'])
+    result = util.recursive_dict_evaluate(dict(cfg))
+    assert result['rdx']['detnum'] == [(1, 5), (2, 6), (3, 7), (4, 8)]
+
+    # Single tuple GMOS style
+    cfg = ConfigObj(['[rdx]', 'detnum = (1,2,3)'])
+    result = util.recursive_dict_evaluate(dict(cfg))
+    assert result['rdx']['detnum'] == [(1, 2, 3)]
+
+    # Int followed by multiple tuples
+    cfg = ConfigObj(['[rdx]', 'detnum = 1,(2,6),(3,7)'])
+    result = util.recursive_dict_evaluate(dict(cfg))
+    assert result['rdx']['detnum'] == [1, (2, 6), (3, 7)]
+
 
 def test_framegroup():
     pypeitpar.FrameGroupPar()
@@ -252,3 +287,5 @@ def test_lists():
     with pytest.raises(TypeError):
         p['calibrations']['alignment']['locations'] = 0.0
         _p = pypeitpar.PypeItPar.from_cfg_lines(cfg_lines=p.to_config())  # Once as tuple
+
+