Raise error when fundamental callback is not implemented

src/pyscipopt/benders.pxi

@@ -35,8 +35,7 @@ cdef class Benders:
 
     def benderscreatesub(self, probnumber):
         '''creates the subproblems and registers it with the Benders decomposition struct '''
-        print("python error in benderscreatesub: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("benderscreatesub() is a fundamental callback and should be implemented in the derived class")
 
     def benderspresubsolve(self, solution, enfotype, checkint):
         '''sets the pre subproblem solve callback of Benders decomposition '''
@@ -60,8 +59,7 @@ cdef class Benders:
 
     def bendersgetvar(self, variable, probnumber):
         '''Returns the corresponding master or subproblem variable for the given variable. This provides a call back for the variable mapping between the master and subproblems. '''
-        print("python error in bendersgetvar: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("bendersgetvar() is a fundamental callback and should be implemented in the derived class")
 
 # local helper functions for the interface
 cdef Variable getPyVar(SCIP_VAR* var):

src/pyscipopt/benderscut.pxi

@@ -21,8 +21,7 @@ cdef class Benderscut:
         pass
 
     def benderscutexec(self, solution, probnumber, enfotype):
-        print("python error in benderscutexec: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("benderscutexec() is a fundamental callback and should be implemented in the derived class")
 
 cdef SCIP_RETCODE PyBenderscutCopy (SCIP* scip, SCIP_BENDERS* benders, SCIP_BENDERSCUT* benderscut) noexcept with gil:
     return SCIP_OKAY

src/pyscipopt/conshdlr.pxi

@@ -55,23 +55,19 @@ cdef class Conshdlr:
 
     def consenfolp(self, constraints, nusefulconss, solinfeasible):
         '''calls enforcing method of constraint handler for LP solution for all constraints added'''
-        print("python error in consenfolp: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("consenfolp() is a fundamental callback and should be implemented in the derived class")
 
     def consenforelax(self, solution, constraints, nusefulconss, solinfeasible):
         '''calls enforcing method of constraint handler for a relaxation solution for all constraints added'''
-        print("python error in consenforelax: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("consenforelax() is a fundamental callback and should be implemented in the derived class")
 
     def consenfops(self, constraints, nusefulconss, solinfeasible, objinfeasible):
         '''calls enforcing method of constraint handler for pseudo solution for all constraints added'''
-        print("python error in consenfops: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("consenfops() is a fundamental callback and should be implemented in the derived class")
 
     def conscheck(self, constraints, solution, checkintegrality, checklprows, printreason, completely):
         '''calls feasibility check method of constraint handler '''
-        print("python error in conscheck: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("conscheck() is a fundamental callback and should be implemented in the derived class")
 
     def consprop(self, constraints, nusefulconss, nmarkedconss, proptiming):
         '''calls propagation method of constraint handler '''
@@ -89,8 +85,7 @@ cdef class Conshdlr:
 
     def conslock(self, constraint, locktype, nlockspos, nlocksneg):
         '''variable rounding lock method of constraint handler'''
-        print("python error in conslock: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("conslock() is a fundamental callback and should be implemented in the derived class")
 
     def consactive(self, constraint):
         '''sets activation notification method of constraint handler '''

src/pyscipopt/event.pxi

@@ -34,8 +34,7 @@ cdef class Eventhdlr:
 
     def eventexec(self, event):
         '''calls execution method of event handler '''
-        print("python error in eventexec: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("eventexec() is a fundamental callback and should be implemented in the derived class")
 
 
 # local helper functions for the interface

src/pyscipopt/heuristic.pxi

@@ -26,8 +26,7 @@ cdef class Heur:
 
     def heurexec(self, heurtiming, nodeinfeasible):
         '''should the heuristic the executed at the given depth, frequency, timing,...'''
-        print("python error in heurexec: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("heurexec() is a fundamental callback and should be implemented in the derived class")
 
 
 

src/pyscipopt/presol.pxi

@@ -25,8 +25,7 @@ cdef class Presol:
 
     def presolexec(self, nrounds, presoltiming):
         '''executes presolver'''
-        print("python error in presolexec: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("presolexec() is a fundamental callback and should be implemented in the derived class")
 
 
 

src/pyscipopt/propagator.pxi

@@ -37,13 +37,11 @@ cdef class Prop:
 
     def propexec(self, proptiming):
         '''calls execution method of propagator'''
-        print("python error in propexec: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("propexec() is a fundamental callback and should be implemented in the derived class")
 
     def propresprop(self, confvar, inferinfo, bdtype, relaxedbd):
         '''resolves the given conflicting bound, that was reduced by the given propagator'''
-        print("python error in propresprop: this method needs to be implemented")
-        return {}
+        raise NotImplementedError("propresprop() is a fundamental callback and should be implemented in the derived class")