Check solving state of model

[Zhanwei-Liu]

I am wondering if it is possible to automatically check the solving status of the model, similar to the examples from GurobiPy：

from gurobipy import GRB

if model.Status == GRB.INF_OR_UNBD:
    pass
if model.Status == GRB.OPTIMAL:
    pass
elif model.Status != GRB.INFEASIBLE:
    pass

I know I can get the solving state via

sol_state = model.get_model_attribute(poi.ModelAttribute.TerminationStatus)

, but I am unsure what should be compared with sol_state, a string or integer？ Could you provide a small example? Thank you!

[metab0t]

For the solver-agnostic attribute, the return value of model.get_model_attribute(poi.ModelAttribute.TerminationStatus) is pyoptinterface.TerminationStatusCode as documented in the table.

status = model.get_model_attribute(poi.ModelAttribute.TerminationStatus)
if status == poi.TerminationStatusCode.OPTIMAL:
    ...
elif status == poi.TerminationStatusCode.INFEASIBLE:
    ...
elif status == poi.TerminationStatusCode.INFEASIBLE_OR_UNBOUNDED
    ...

The concept is the same as JuMP.jl and I have followed the same logic in Gurobi.jl
https://jump.dev/JuMP.jl/stable/manual/solutions/#Why-did-the-solver-stop?
https://jump.dev/JuMP.jl/stable/moi/reference/models/#MathOptInterface.TerminationStatusCode

Of course, you can also query the Gurobi-specific status as documented in https://metab0t.github.io/PyOptInterface/gurobi.html#attribute and https://www.gurobi.com/documentation/current/refman/attributes.html#sec:Attributes

import pyoptinterface as poi
from pyoptinterface import gurobi
GRB = gurobi.GRB

status = model.get_model_raw_attribute("Status")
if status == GRB.INF_OR_UNBD:
    pass
if status == GRB.OPTIMAL:
    pass
elif status == GRB.INFEASIBLE:
    pass

The GRB submodule has exported most constants like GRB in gurobipy and I will figure out how to introduce it in our documentation.

[metab0t]

@Zhanwei-Liu I have updated the code and documentation for pyoptinterface.gurobi.GRB and pyoptinterface.copt.COPT. Now they are exactly identical to gurobipy.GRB and coptpy.COPT because I write a script to ensure that.

[Zhanwei-Liu]

Great! Thank you for your update!