issue117.py

from collections import namedtuple
from ortools.constraint_solver import pywrapcp

VEHICLE_COUNT= 30
VEHICLE_CAPACITY = 200


Customer = namedtuple("Customer", ['index', 'demand', 'x', 'y'])

print (' ----------------------------------------------- Init ----------------------------------------------')

customers = list()
customers.append(Customer(0,0,0,0))
customers.append(Customer(1,1,1.0,1.0))
customers.append(Customer(1,1,2.0,2.0))
customer_count = len(customers)


routing = pywrapcp.RoutingModel(3, VEHICLE_COUNT)
routing.SetDepot(0)

print (' ----------------------------------------------- Demand Constraint ---------------------------------------')
demands=[]
for i in range(0, customer_count):
    demands.append(customers[i][1])
routing.AddVectorDimension(demands, VEHICLE_CAPACITY, True,"Demand")

print (' ----------------------------------------------- Adding Costs ---------------------------------------')
def length(customer1, customer2):
    #static just for the sake of the example
    return 1
routing.SetCost(length)

routing.CloseModel()

assignment=routing.Solve(None)

# Inspect solution and extract routes
routes=[]
for i in range(0, routing.vehicles()):

    route_number = i
    routes.append([])
    node = routing.Start(route_number)
    route=[]
    route.append(0)
    if routing.IsVehicleUsed(assignment, i):
        while True:
            node = assignment.Value(routing.NextVar(node))

            if not routing.IsEnd(node):
                route.append(int(node))
            else :
                break

    route.append(0)
    routes[route_number].append(route)

#This are the routes as list of lists
routes = [el[0] for el in routes]

#Now try to read the routes into a new assigment object fails
assignment2 = routing.ReadAssignmentFromRoutes(routes,True)