how to output the decision variable values in gurobi?
I have two decision variables in my model, but I do not know how to return the value of these decision variables seperately.
import pandas as pd
import gurobipy as gpy
string = '/Users/user/Desktop/ISE 402/distance_matrix.csv'
df = pd.read_csv(string,index_col=0) #input the distance matrix c_ij
#save the index and column of the distance matrix
index = df.index #Chicago school #行
column = df.columns #Chicago libraries #列
#create the model
model = gpy.Model(name='8.12(a)')
x = model.addVars(column,vtype=gpy.GRB.BINARY,name='x') #=1 if we build the library
y = model.addVars(index, vtype=gpy.GRB.BINARY,name='y') #=1 if the school is covered
model.update()
#set the objective function
model.setObjective(gpy.quicksum(y[i] for i in index),sense=gpy.GRB.MAXIMIZE)
#add the constraints
model.addConstr(gpy.quicksum(x[j] for j in column)<=12)
model.addConstrs(y[i]<=gpy.quicksum(df.at[i,j]*x[j] for j in column)for i in index)
#optimization
model.optimize()
print("Obj: ",model.objVal)

You can simply look at the X attribute of your variables. Here is an example of how to do this in Python. Before accessing the X attribute, please make sure to check if a solution is available. If you are trying to query the solution values, but there is no solution this will result in an error.
Best,
Sonja
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