KeyError 0 - Gurobi - Jupyter Notebook

Answered

UNAL INCE

May 16, 2023 13:35

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I have KeyError 0 in knapsack problem. Could you please help about this issue?

My code details below;

 

import gurobipy as gp
from gurobipy import GRB

import pandas as pd

v=pd.read_excel('C:\\Users\\INCE\\Desktop\\gurobidata.xlsx',usecols=[1])
v




w=pd.read_excel('C:\\Users\\INCE\\Desktop\\gurobidata.xlsx',usecols=[2])
w

c=1000
N=len(w)

from gurobipy import *

knapsack_model=Model('knapsack')

x=knapsack_model.addVars(N,vtype=GRB.BINARY,name='x')

obj_fn=sum(v[i]*x[i] for i in range (N))
knapsack_model.setObjective(obj_fn,GRB.MAXIMIZE)

knapsack_model.addConstr(sum(w[i]*x[i] for i in range (N))<=c)
knapsack_model.update()

knapsack_model.setParam('OutputFlag',False)
knapsack_model.optimize()
print('Optimization is done. Objective Function Value: %.2f' %knapsack_model.objVal)
for v in knapsack_model.getVars():
    print ('%s: %g' %(v.varName,v.x))

0

• 

  Marika Karbstein

  • Gurobi Staff

  May 16, 2023 16:02

  Your data v and w cannot be used in this way. 

  If gurobidata.xlsx is a table with headings 'weight' and 'capacity', you could do the following

  df=pd.read_excel('gurobidata.xlsx')
  v = df['weight'].tolist()
  w = df['capacity'].tolist()

  0

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