Add first model feature (constraint RHS)

miplearn/features.py

@@ -0,0 +1,26 @@
+#  MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
+#  Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
+#  Released under the modified BSD license. See COPYING.md for more details.
+
+from typing import TYPE_CHECKING
+
+from miplearn.types import ModelFeatures
+
+if TYPE_CHECKING:
+    from miplearn import InternalSolver
+
+
+class ModelFeaturesExtractor:
+    def __init__(
+        self,
+        internal_solver: "InternalSolver",
+    ) -> None:
+        self.internal_solver = internal_solver
+
+    def extract(self) -> ModelFeatures:
+        rhs = {}
+        for cid in self.internal_solver.get_constraint_ids():
+            rhs[cid] = self.internal_solver.get_constraint_rhs(cid)
+        return {
+            "ConstraintRHS": rhs,
+        }