support for python3.13

.github/workflows/github-ci.yml

@@ -10,12 +10,12 @@ jobs:
 
     steps:
 
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Set up Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
-          python-version: 3.11
+          python-version: 3.13
 
       - name: Upgrade pip
         run: python -m pip install --upgrade pip
@@ -39,7 +39,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "pypy3.9-v7.3.15"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12","3.13", "pypy3.9-v7.3.15"]
         os: [macos-11, macos-12, ubuntu-20.04, ubuntu-22.04, windows-2019, windows-2022]
         exclude:
           # temporarily exclude pypy3 on mac-os as there failing tests caused by bug on cbc side
@@ -50,14 +50,22 @@ jobs:
 
     steps:
 
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
         architecture: x64
-        cache: 'pip'
+
+    - name: Cache pip dependencies
+      uses: actions/cache@v4
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ matrix.python-version }}-${{ hashFiles('**/pyproject.toml') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-${{ matrix.python-version }}-
+          ${{ runner.os }}-pip-
 
     - name: Check python version
       run: python -c "import sys; import platform; print('Python %s implementation %s on %s' % (sys.version, platform.python_implementation(), sys.platform))"

mip/highs.py

@@ -30,16 +30,21 @@
         # need library matching operating system
         platform = sys.platform.lower()
         if "linux" in platform:
-            pattern = "highs_bindings.*.so"
+            patterns = ["highs_bindings.*.so", "_core.*.so"]
         elif platform.startswith("win"):
-            pattern = "highs_bindings.*.pyd"
+            patterns = ["highs_bindings.*.pyd", "_core.*.pyd"]
         elif any(platform.startswith(p) for p in ("darwin", "macos")):
-            pattern = "highs_bindings.*.so"
+            patterns = ["highs_bindings.*.so", "_core.*.so"]
         else:
             raise NotImplementedError(f"{sys.platform} not supported!")
 
         # there should only be one match
-        [libfile] = glob.glob(os.path.join(pkg_path, pattern))
+        matched_files = []
+        for pattern in patterns:
+            matched_files.extend(glob.glob(os.path.join(pkg_path, pattern)))
+        if len(matched_files) != 1:
+            raise FileNotFoundError(f"Could not find HiGHS library in {pkg_path}.")
+        [libfile] = matched_files
         logger.debug("Choosing HiGHS library {libfile} via highspy package.")
 
     highslib = ffi.dlopen(libfile)

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

@@ -471,7 +471,7 @@ 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 +484,7 @@ 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]
 

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "setuptools.build_meta"
 name = "mip"
 description = "Python tools for Modeling and Solving Mixed-Integer Linear Programs (MIPs)"
 readme = "README.md"
-requires-python = ">=3.7,<3.13"
+requires-python = ">=3.7,<3.14"
 license = {file = "LICENSE"}
 authors = [
     {name="Tulio A.M. Toffolo", email="[email protected]"},
@@ -25,7 +25,7 @@ classifiers = [
     "Development Status :: 5 - Production/Stable",
     "License :: OSI Approved :: Eclipse Public License 2.0 (EPL-2.0)",
     "Operating System :: OS Independent",
-    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
     "Topic :: Scientific/Engineering :: Mathematics"
@@ -41,7 +41,7 @@ numpy = [
     "numpy==1.21.*; python_version=='3.7'"
 ]
 gurobi = ["gurobipy>=8"]
-highs = ["highspy>=1.5.3; python_version<='3.11'"]
+highs = ["highspy>=1.6.0"]
 test = [
     "pytest>=7.4",
     "networkx==2.8.8; python_version>='3.8'",