Pyomo can't find Gurobi solver

Question

I have a pyomo model that I can solve using the GLPK solver by just using the code:

solver = pyo.SolverFactory('glpk')
solver.options['mipgap'] = 0.02
solution = solver.solve(model, tee=True)

Now I have installed the academic version of Gurobi on my computer. However I can't use Gurobi when having the code:

solver = pyo.SolverFactory('gurobi', solver_io="python")
solver.options['mipgap'] = 0.02
solution = solver.solve(model, tee=True)

I get the error message:

ApplicationError: No Python bindings available for <class 'pyomo.solvers.plugins.solvers.gurobi_direct.GurobiDirect'> solver plugin

Now I found this discussion on Stackoverflow Pyomo can't use Gurobi solver I did what the accepted answer advices. I used the windows cmd and navigated to my installation path of Gurobi. I tried two different folders

• C:\Gurobi\win64\
• C:\Gurobi\

and I use the suggested command

python setup.py install

However, I get an error message in the cmd of Windows telling that the command 'python' can't be found or is wrong. Do you know what I have to do in order to use Gurobi with Pyomo in Python?

Answer 1

The mentioned link is about using gurobipy (gurobi's interface for python) to model your problem and solve it using gurobi. If you want to model the problem using Pyomo and use gurobi as a solver, you need to add the gurobi solver to the system's path. For that do the followings:

1. In Windows search for Edit the system environment variables (I am not familiar with Mac OS).
2. Open Environment Variables
3. In the System variables window click on Path and add the folder that includes your gurobi.exe

then use the following in your code:

solver = pyo.SolverFactory('gurobi')
solver.options['MIPGap'] = 0.02
solution = solver.solve(model, tee=True)