File "src\gurobipy\var.pxi", line 125, in gurobipy.Var.__getattr__ File "src\gurobipy\var.pxi", line 153, in gurobipy.Var.getAttr File "src\gurobipy\attrutil.pxi", line 100, in gurobipy.__getattr AttributeError: Unable to retrieve attribute 'x'. Did y

Did you solve the optimization problem and call the `optimize()` method before trying to access the value of the decision variables? The error message suggests that the `x` attribute cannot be retrieved because the optimization problem has not been solved yet.

In Gurobi, the `x` attribute of a decision variable returns its optimal value after the optimization problem has been solved. Therefore, you need to make sure that you call the `optimize()` method before trying to access this attribute. Here's an example:

# Define the optimization model and add variables, constraints, and objective

model.optimize()

# Check if the optimization was successful
if model.status == GRB.OPTIMAL:
    # Access the value of the decision variables
    for var in model.getVars():
        print(var.varName, var.x)
else:
    print('Optimization was not successful')

Note that you need to check the status of the optimization problem before accessing the value of the decision variables, as the `x` attribute may not be available if the optimization was not successful.