Merge pull request #1256 from arcondello/fix/CQM-from_file-weight-type

Fix the weight type in CQMs with soft constraints loaded from files

dimod/constrained.py

@@ -1209,7 +1209,7 @@ def from_file(cls,
                 label = deserialize_variable(json.loads(constraint))
 
                 try:
-                    weight = np.frombuffer(zf.read(f"constraints/{constraint}/weight"))
+                    weight = np.frombuffer(zf.read(f"constraints/{constraint}/weight"), np.float64)[0]
                     penalty = zf.read(f"constraints/{constraint}/penalty").decode('ascii')
                 except KeyError:
                     weight = None

releasenotes/notes/fix-CQM.from_file-weight-type-968e7f0bbf2e07ce.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fix the type of soft constraint weights when loaded from files. The issue was
+    introduced in 0.11.6.dev1.

tests/test_constrained.py

@@ -14,6 +14,7 @@
 
 import itertools
 import json
+import numbers
 import unittest
 
 from textwrap import dedent
@@ -1059,6 +1060,7 @@ def test_functional_soft(self):
 
         for label, info in cqm._soft.items():
             self.assertEqual(info.weight, new._soft[label].weight)
+            self.assertIsInstance(new._soft[label].weight, numbers.Number)
             self.assertEqual(info.penalty, new._soft[label].penalty)
 
     def test_header(self):