Variable object mapping issue in Python Callbacks with Presolve enabled

Hi Chris.

Thank you for your response.

I am using Xpress 9.6.0 and Python 3.13.9.

I am still a bit confused about how to properly access variables in the callback. I have included a skeleton of my code below. Could you please explain how I can modify it to access the variables correctly with presolve?

In addition, if there is any better way to get solution in callback using getCallbackSolution?

class XpressSolver():
    def __init__(self):
        ....
 
    def build(self):
        self.prob = xp.problem()
 
        x = self.model.addVariables(..., name='x')
        y = self.model.addVariables(..., name='y')
 
        self.variables['x'] = x
        self.variables['y'] = y
 
        ........
 
    def PreIntSolCallback(self, model, object, soltype, cutoff):
        x = self.variables['x']
        y = self.variables['y']
        ....
 
        x_sol, y_sol = {},{}
        for key, value in x.items():
            x_sol[key] = model.getCallbackSolution(value)
        for key, value in y.items():
            y_sol[key] = model.getCallbackSolution(value)
......