Creating binary variables with mutiple indices in gurobi

Question

I am pretty new to Python and Gurobi. I want to add a binary variable for several "dimensions":

A = [1,2,3,4]
B = [1,2,3,4]
C = [1,2,3,4,5]
D = [1,2,3]

I need the binary variable x with indices A,B,C,D.

I am not sure how to use the command:

m.addVars()

Answer 1

This is how you create variables from a given index list:

import gurobipy as gp

A = [1,2,3,4]
model = gp.Model()
variables = model.addVars(A, name='A', vtype='B')

After calling model.update() , you see these variable names/types:

{1: <gurobi.Var A[1]>,
 2: <gurobi.Var A[2]>,
 3: <gurobi.Var A[3]>,
 4: <gurobi.Var A[4]>}

This is also explained in the documentation . You simply repeat this process for the other lists B , C , and D .

EDIT

Another alternative to combine all indices into one variable structure is the following:

A = [1,2,3,4]
B = [1,2]
C = [1,2,3]
model = gp.Model()
variables = model.addVars(A, B, C, vtype='B')

You would access these variables like this:

variables[1,2,1]