fixed python3.13 processing structures in side mip/lists.py and mip/model.py

Author: miguelhisojo

mip/lists.py

@@ -49,6 +49,8 @@ def add(
         return new_var
 
     def __getitem__(self: "VarList", key):
+        if key is None:
+            raise KeyError("Empty key access (e.g., varlist[]) is not allowed in Python 3.13")
         if isinstance(key, str):
             return self.__model.var_by_name(key)
         return self.__vars[key]

mip/model.py

@@ -53,6 +53,23 @@ def __init__(
         solver: Optional[mip.Solver] = None,
     ):
         """Model constructor
+tests/unit/test_portfolio_optimisation/hs/execution/reports/test_aantal_ibn_report.py:29 (TestCaseAantalIBNReport.test_aantal_ibn_vraag_overview)
+2 != 3
+
+Expected :3
+Actual   :2
+<Click to see difference>
+
+cls = <class 'tests.unit.test_portfolio_optimisation.hs.execution.reports.test_aantal_ibn_report.TestCaseAantalIBNReport'>
+
+    @classmethod
+    def setUp(cls):
+        cls.portfolio = dummy_hs_portfolio()
+>       model, result = optimize_plan(cls.portfolio)
+                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+tests/unit/test_portfolio_optimisation/hs/execution/reports/test_aantal_ibn_report.py:27: AssertionError
+
 
         Creates a Mixed-Integer Linear Programming Model. The default model
         optimization direction is Minimization. To store and optimize the model
@@ -471,7 +488,7 @@ def constr_by_name(self: "Model", name: str) -> Optional["mip.Constr"]:
             constraint or None if not found
         """
         cidx = self.solver.constr_get_index(name)
-        if cidx < 0 or cidx > len(self.constrs):
+        if cidx < 0 or cidx >= len(self.constrs):
             return None
         return self.constrs[cidx]
 
@@ -484,7 +501,7 @@ def var_by_name(self: "Model", name: str) -> Optional["mip.Var"]:
             Variable or None if not found
         """
         v = self.solver.var_get_index(name)
-        if v < 0 or v > len(self.vars):
+        if v < 0 or v >= len(self.vars):
             return None
         return self.vars[v]