Pyomo: Access Solution From Python Code

Question

I have a linear integer programme I want to solve. I installed solver glpk (thanks to this answer) and pyomo. I wrote code like this:

from pyomo.environ impo         


        

Answer 1

I found the pyomoio module in the urbs project. It extracts sets, parameters, variables, and so on, and the returns them in pandas objects, which are very convenient for visualization in jupyter notebooks.

I build a simple model

model = ConcreteModel()
model.act = Set(initialize=list('IJK'))
model.goods = Set(initialize=list('ijk'))
u0 = {}
u0['i', 'J'] = 2.
u0['k', 'I'] = .3
model.U0 = Param(model.goods, model.act, initialize=u0, default=0)

I can then read it in a pandas DataFrame, with all the labels set appropriately.

import pyomoio as po
u_df = po.get_entity(model, 'U0').unstack()
print(u_df)

# act      I    J    K
# goods               
# i      0.0  2.0  0.0
# j      0.0  0.0  0.0
# k      0.3  0.0  0.0