Error when assigning binary variable type ('GRB' is not defined)

Answered

Nicolas Gomez

August 17, 2020 00:40

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• 

Hi,

I'm encountering what I think is a very simple error but haven't figured out how to fix it. When assigning binary variable type to my model in Python, I keep getting the error that 'GRB' is not defined:

xij = m.addMVar(nx, vtype=GRB.BINARY)

returns

name 'GRB' is not defined

What am I missing? I updated to the latest Gurobi version and checked it is correctly installed.

 

Thanks!

1

• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  December 06, 2024 00:42

  This post is more than three years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum. Or why not try our AI Gurobot?.
• 

  Sonja Mars

  • Gurobi Staff

  August 17, 2020 06:14

  Hi Nicolas,

  This is probably a problem with the import of the Gurobi Python module. In our examples we do the following:

  import gurobipy as gp
  from gurobipy import GRB

  If these lines are present before you actually want to use something from our Python module (so normally, you would add them in the beginning of your file), your code should work fine. Please also see our mip1.py example.

  Best,

    Sonja

  1

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