Gurobi Python Error: list index out of range

Question

在 Zeppelin (oracle data studio) 中使用 Gurobi 时，我不断收到列表索引错误。这是代码和错误消息。 Gurobi 的新手，非常感谢任何有关如何解决此问题的有用意见。

将变量（数量）添加到模型（交易）时似乎出现错误

%python
import numpy as np
import pandas as pd
import gurobipy as gp
from gurobipy import *
from rsecommon.analytics.gurobi import *
try:

    instance = rseenv.RseGurobiEnv.getInstance()
    env = instance.getGurobiEnv()
    # Model
    deal = Model("Deal Optimization", env)
    
    # Parameters
    items = ['item1', 'item2', 'item3', 'item4', 'item5', 'item6', 'item7', 'item8', 'item9', 'item10']
    volumes = {'item1':1, 'item2':1, 'item3':2, 'item4':2, 'item5':3, 'item6':3, 'item7':4, 'item8':4, 'item9':5, 'item10':5}
    discounts = {'item1':0.05, 'item2':0.04, 'item3':0.01, 'item4':0.08, 'item5':0.06, 'item6':0.02, 'item7':0.01, 'item8':0.09, 'item9':0.06, 'item10':0.09}
    min_qty = {'item1':540, 'item2':70, 'item3':220, 'item4':170, 'item5':60, 'item6':850, 'item7':910, 'item8':310, 'item9':480, 'item10':60}

    capacity_cap = 5000

    # Variables
    quantity = deal.addVars(items, ub = (5000/volumes[item] for item in volumes),name='quantity')
    
    # Constraints
    deal.addConstr(((gp.quicksum(volumes[item]*quantity[item] for item in volumes) <= capacity_cap )), "Capacity")

    # Set objective
    deal.setObjective(quantity.prod(discounts), GRB.MAXIMIZE) 

    # Optimize
    deal.optimize()

    for v in deal.getVars():
        print('%s %g' % (v.varName, v.x))

    print('Obj: %g' % deal.objVal)

except GurobiError as e:
    print('Error code ' + str(e.errno) + ": " + str(e.message))

except AttributeError:
    print('Enco111untered an attribute error')

错误信息：

Traceback (most recent call last):
  File "/tmp/zeppelin_python-2988405025033753797.py", line 312, in <module>
    exec(code, _zcUserQueryNameSpace)
  File "<stdin>", line 15, in <module>
  File "model.pxi", line 2496, in gurobipy.Model.addVars
IndexError: list index out of range

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/tmp/zeppelin_python-2988405025033753797.py", line 319, in <module>
    raise Exception(traceback.format_exc())
Exception: Traceback (most recent call last):
  File "/tmp/zeppelin_python-2988405025033753797.py", line 312, in <module>
    exec(code, _zcUserQueryNameSpace)
  File "<stdin>", line 15, in <module>
  File "model.pxi", line 2496, in gurobipy.Model.addVars
IndexError: list index out of range

Answer 1

尝试在对 Model.addVars 的调用中使用 UB 值的字典：

quantity = deal.addVars(items,
                        ub = {item:5000/volumes[item] for item in items},
                        name='quantity')

Gurobi Python Error: list index out of range

Gurobi Python Error: list index out of range

python

gurobi

apache-zeppelin