[Depends on #3703] Direct and Persistent Interfaces to SCIP

.github/workflows/test_branches.yml

@@ -294,6 +294,12 @@ jobs:
                 || echo "WARNING: Xpress Community Edition is not available"
             python -m pip install --cache-dir cache/pip maingopy \
                 || echo "WARNING: MAiNGO is not available"
+            if [[ ${{matrix.python}} == pypy* ]]; then
+                echo "skipping SCIP for pypy"
+            else
+                python -m pip install --cache-dir cache/pip pyscipopt \
+                    || echo "WARNING: SCIP is not available"
+            fi
             if [[ ${{matrix.python}} == pypy* ]]; then
                 echo "skipping wntr for pypy"
             else
@@ -390,7 +396,7 @@ jobs:
             TIMEOUT_MSG="TIMEOUT: killing conda install process"
             PYVER=$(echo "py${{matrix.python}}" | sed 's/\.//g')
             echo "Installing for $PYVER"
-            for PKG in 'cplex>=12.10' docplex gurobi "$XPRESS" cyipopt pymumps scip; do
+            for PKG in 'cplex>=12.10' docplex gurobi "$XPRESS" cyipopt pymumps scip pyscipopt; do
                 echo ""
                 echo "*** Install $PKG ***"
                 echo ""

.github/workflows/test_pr_and_main.yml

@@ -360,6 +360,12 @@ jobs:
                 || echo "WARNING: Xpress Community Edition is not available"
             python -m pip install --cache-dir cache/pip maingopy \
                 || echo "WARNING: MAiNGO is not available"
+            if [[ ${{matrix.python}} == pypy* ]]; then
+                echo "skipping SCIP for pypy"
+            else
+                python -m pip install --cache-dir cache/pip pyscipopt \
+                    || echo "WARNING: SCIP is not available"
+            fi
             if [[ ${{matrix.python}} == pypy* ]]; then
                 echo "skipping wntr for pypy"
             else
@@ -456,7 +462,7 @@ jobs:
             TIMEOUT_MSG="TIMEOUT: killing conda install process"
             PYVER=$(echo "py${{matrix.python}}" | sed 's/\.//g')
             echo "Installing for $PYVER"
-            for PKG in 'cplex>=12.10' docplex gurobi "$XPRESS" cyipopt pymumps scip; do
+            for PKG in 'cplex>=12.10' docplex gurobi "$XPRESS" cyipopt pymumps scip pyscipopt; do
                 echo ""
                 echo "*** Install $PKG ***"
                 echo ""

pyomo/contrib/observer/__init__.py

@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2025
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________

pyomo/contrib/observer/component_collector.py

@@ -0,0 +1,117 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2025
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.core.expr.visitor import StreamBasedExpressionVisitor
+from pyomo.core.expr.numeric_expr import (
+    ExternalFunctionExpression,
+    NegationExpression,
+    PowExpression,
+    MaxExpression,
+    MinExpression,
+    ProductExpression,
+    MonomialTermExpression,
+    DivisionExpression,
+    SumExpression,
+    Expr_ifExpression,
+    UnaryFunctionExpression,
+    AbsExpression,
+)
+from pyomo.core.expr.relational_expr import (
+    RangedExpression,
+    InequalityExpression,
+    EqualityExpression,
+)
+from pyomo.core.base.var import VarData, ScalarVar
+from pyomo.core.base.param import ParamData, ScalarParam
+from pyomo.core.base.expression import ExpressionData, ScalarExpression
+from pyomo.repn.util import ExitNodeDispatcher
+from pyomo.common.numeric_types import native_numeric_types
+
+
+def handle_var(node, collector):
+    collector.variables[id(node)] = node
+    return None
+
+
+def handle_param(node, collector):
+    collector.params[id(node)] = node
+    return None
+
+
+def handle_named_expression(node, collector):
+    collector.named_expressions[id(node)] = node
+    return None
+
+
+def handle_external_function(node, collector):
+    collector.external_functions[id(node)] = node
+    return None
+
+
+def handle_skip(node, collector):
+    return None
+
+
+collector_handlers = ExitNodeDispatcher()
+collector_handlers[VarData] = handle_var
+collector_handlers[ParamData] = handle_param
+collector_handlers[ExpressionData] = handle_named_expression
+collector_handlers[ScalarExpression] = handle_named_expression
+collector_handlers[ExternalFunctionExpression] = handle_external_function
+collector_handlers[NegationExpression] = handle_skip
+collector_handlers[PowExpression] = handle_skip
+collector_handlers[MaxExpression] = handle_skip
+collector_handlers[MinExpression] = handle_skip
+collector_handlers[ProductExpression] = handle_skip
+collector_handlers[MonomialTermExpression] = handle_skip
+collector_handlers[DivisionExpression] = handle_skip
+collector_handlers[SumExpression] = handle_skip
+collector_handlers[Expr_ifExpression] = handle_skip
+collector_handlers[UnaryFunctionExpression] = handle_skip
+collector_handlers[AbsExpression] = handle_skip
+collector_handlers[RangedExpression] = handle_skip
+collector_handlers[InequalityExpression] = handle_skip
+collector_handlers[EqualityExpression] = handle_skip
+
+
+class _ComponentFromExprCollector(StreamBasedExpressionVisitor):
+    def __init__(self, **kwds):
+        self.named_expressions = {}
+        self.variables = {}
+        self.params = {}
+        self.external_functions = {}
+        super().__init__(**kwds)
+
+    def exitNode(self, node, data):
+        if type(node) in native_numeric_types:
+            # we need this here to handle numpy
+            # (we can't put numpy in the dispatcher?)
+            return None
+        return collector_handlers[node.__class__](node, self)
+
+    def beforeChild(self, node, child, child_idx):
+        if id(child) in self.named_expressions:
+            return False, None
+        return True, None
+
+
+_visitor = _ComponentFromExprCollector()
+
+
+def collect_components_from_expr(expr):
+    _visitor.__init__()
+    _visitor.walk_expression(expr)
+    return (
+        list(_visitor.named_expressions.values()),
+        list(_visitor.variables.values()),
+        list(_visitor.params.values()),
+        list(_visitor.external_functions.values()),
+    )