优化代码“def calTravelCost(route_list, model): timetable_list = [] distance_of_routes = 0 time_of_routes = 0 obj = 0 for route in route_list: timetable = [] vehicle = model.vehicle_dict[route[0]] v_type = route[0] free_speed = vehicle.free_speed fixed_cost = vehicle.fixed_cost variable_cost = vehicle.variable_cost for i, node_id in enumerate(route): if i == 0: next_node_id = route[i + 1] travel_distance, travel_time, departure = _compute_departure_time(model, v_type, next_node_id, free_speed, 0) elif i < len(route) - 1: last_node_id = route[i - 1] current_node = model.demand_dict[node_id] travel_distance, travel_time, arrival, departure = _compute_arrival_and_departure_time(model, last_node_id, current_node, free_speed, timetable[-1][1]) timetable.append((int(arrival), int(departure))) else: last_node_id = route[i - 1] travel_distance, travel_time, departure = _compute_departure_time(model, last_node_id, v_type, free_speed, timetable[-1][1]) timetable.append((int(departure), int(departure))) distance_of_routes += travel_distance time_of_routes += travel_time if model.opt_type == 0: obj += fixed_cost + distance_of_routes * variable_cost else: obj += fixed_cost + time_of_routes * variable_cost timetable_list.append(timetable) return timetable_list, time_of_routes, distance_of_routes, obj def _compute_departure_time(model, from_node_id, to_node_id, free_speed, arrival_time): travel_distance = model.distance_matrix[from_node_id, to_node_id] travel_time = travel_distance / free_speed departure_time = max(arrival_time, model.demand_dict[to_node_id].start_time - travel_time) return travel_distance, travel_time, departure_time def _compute_arrival_and_departure_time(model, from_node_id, to_node, free_speed, arrival_time): travel_distance = model.distance_matrix[from_node_id, to.id] travel_time = travel_distance / free_speed arrival_time = max(arrival_time + travel_time, to.start_time) departure_time = arrival_time + to.service_time return travel_distance, travel_time, arrival_time, departure_time”

这段代码主要是计算一组路线的时间和距离成本，并返回每个节点的出发和到达时间。其中，_compute_departure_time()函数计算从一个节点到下一个节点的出发时间，_compute_arrival_and_departure_time()函数计算到达一个节点的时间和离开时间，calTravelCost()函数是对这两个函数的封装，用于计算整个路线的时间和距离成本，并返回时间表、时间成本、距离成本和总成本。如果需要优化这段代码，可以考虑使用并行计算来提高计算效率，或者使用更高效的算法来计算时间和距离成本。此外，还可以考虑优化代码结构和变量命名，以提高代码的可读性和可维护性。