Using Gurobi in Python and adding variables - python-2.7

Question

I am trying to write my first Gurobi optimization code and this is where I am stuck with:
I have the following dictionary for my first subscript:
input for k in range(1,11):
i[k] = int(k)
print i
output {1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9, 10: 10}
And, I have the following dictionaries for my second subscript:
c_il = {1: 2, 2: 1, 3: 1, 4: 4, 5: 3, 6: 4, 7: 3, 8: 2, 9: 1, 10: 4}
c_iu = {1: 3, 2: 2, 3: 2, 4: 5, 5: 4, 6: 5, 7: 4, 8: 3, 9: 2, 10: 5}
I am trying to create variables as following:
x = m.addVars(i, c_il, vtype=GRB.BINARY, name="x")
x = m.addVars(i, c_iu, vtype=GRB.BINARY, name="x")
Apparently, it is not giving what I am looking for. What I am looking for is x_(i),(c_il) and x_(i),(c_iu); ignore parenthesis.
More clearly, the following is what I am trying to obtain by using dicts i, c_il, and c_iu:
{1: <gurobi.Var x[1,2]>,
2: <gurobi.Var x[2,1]>,
3: <gurobi.Var x[3,1]>,
4: <gurobi.Var x[4,5]>,
5: <gurobi.Var x[5,3]>,
6: <gurobi.Var x[6,4]>,
7: <gurobi.Var x[7,3]>,
8: <gurobi.Var x[8,2]>,
9: <gurobi.Var x[9,1]>,
10: <gurobi.Var x[10,4]>,
11: <gurobi.Var x[1,3]>,
12: <gurobi.Var x[2,2]>,
13: <gurobi.Var x[3,2]>,
14: <gurobi.Var x[4,5]>,
15: <gurobi.Var x[5,4]>,
16: <gurobi.Var x[6,5]>,
17: <gurobi.Var x[7,4]>,
18: <gurobi.Var x[8,3]>,
19: <gurobi.Var x[9,2]>,
20: <gurobi.Var x[10,5]>}
Since I am using dictionaries everywhere, I want to keep it consistent by continuing to use dictionaries so that I can do multiplications and additions with my parameters which are all in dictionaries. Is there any way to create these variables with m.addVars or m.addVar?
Thanks!
Edit: Modified to make it more clear.

Answer 1

It looks like you want to create 10 variables that are indexed by something. The best way to do this is to create the two indexes as lists. If you want x[12], x[21], then write:
from gurobipy import *
m = Model()
il = [ 12, 21, 31, 44, 53, 64, 73, 82, 91, 104 ]
x = m.addVars(il, vtype=GRB.BINARY, name="x")
And if you want to write x[1,2], x[2,1], then write:
from gurobipy import *
m = Model()
il = [ (1,2), (2,1), (3,1), (4,4), (5,3), (6,4), (7,3), (8,2), (9,1), (10,4) ]
x = m.addVars(il, vtype=GRB.BINARY, name="x")

Answer 2

After a few years of experience, I can easily write the below as an answer. Since the past myself was concerned with keeping the dictionaries as is (I highly criticize and question...), a quick solution is as follows.
x = {}
for (i,j) in c_il.items():
x[i,j] = m.addVar(vtype=GRB.BINARY, name="x%s"%str([i,j]))
for (i,j) in c_iu.items():
x[i,j] = m.addVar(vtype=GRB.BINARY, name="x%s"%str([i,j]))
Alternatively,
x = {(i,j): m.addVar(vtype=GRB.BINARY, name="x%s"%str([i,j]))
for (i,j) in c_il.items()}
for (i,j) in c_iu.items():
x[i,j] = m.addVar(vtype=GRB.BINARY, name="x%s"%str([i,j]))
One liner alternative:
x = {(i,j): m.addVar(vtype=GRB.BINARY, name="x%s"%str([i,j]))
for (i,j) in [(k,l) for (k,l) in c_il.items()] + [(k,l) for (k,l) in c_iu.items()]}