Question

在django应用中显示图表

这是我的Views.py

def json_example(request):
    return render(request, 'classroom/teachers/json_example.html')

def chart_data(request):
    dataset = DispatchPlan.objects.all()
    print("dataset is ", dataset)

    # port_display_name = dict()
    # for port_tuple in Passenger.PORT_CHOICES:
    #     port_display_name[port_tuple[0]] = port_tuple[1]

    chart = {
        'chart': {'type': 'pie'},
        'title': {'text': 'Titanic Survivors by Ticket Class'},
        'series': [{
            'name': 'Embarkation Port',
            'data': list(map(lambda row: {'name': row['weight'], 'y': row['route_distance']}, dataset))
        }]
    }

    return JsonResponse(chart)

当我运行该应用程序时，它显示以下错误：

TypeError：“ DispatchPlan”对象不可下标

在此行

'data': list(map(lambda row: {'name': row['weight'], 'y': row['route_distance']}, dataset))

我猜是因为我没有正确映射它，我该如何解决？

跟踪：

文件   “ C：\ Users \ Sid \ AppData \ Local \ Programs \ Python \ Python37 \ lib \ site-packages \ django \ core \ handlers \ exception.py”   在内部     35. response = get_response（request）

文件   “ C：\ Users \ Sid \ AppData \ Local \ Programs \ Python \ Python37 \ lib \ site-packages \ django \ core \ handlers \ base.py”   在_get_response中     128. response = self.process_exception_by_middleware（e，request）

文件   “ C：\ Users \ Sid \ AppData \ Local \ Programs \ Python \ Python37 \ lib \ site-packages \ django \ core \ handlers \ base.py”   在_get_response中     126. response = wrapd_callback（request，* callback_args，** callback_kwargs）

文件   “ D：\ Downloads-HDD \ aggregator-master \ django_school \ classroom \ views \ teachers.py”   在chart_data中     884.'data'：[{'name'：row.weight，'y'：row.route_distance}用于数据集中的行]

文件   “ D：\ Downloads-HDD \ aggregator-master \ django_school \ classroom \ views \ teachers.py”   在     884.'data'：[{'name'：row.weight，'y'：row.route_distance}用于数据集中的行]

异常类型：/ shipper / json-example / data /中的AttributeError   异常值：“ dict”对象没有属性“ weight”

Models.py

class DispatchPlan(models.Model):
    bid_status_choices = (
        ('Hold', 'Hold'), ('Active', 'Active'), ('Assigned', 'Assigned'), ('Dispatched', 'Dispatched'),
        ('Delayed', 'Delayed'), ('Delivered', 'Delivered'))
    mtypes = (('Fragile', 'Fragile'), ('Non-Fragile', 'Non-Fragile'))

    owner = models.ForeignKey(User, on_delete=models.CASCADE, related_name='dispatch_quizzes')
    comments = models.TextField(max_length=256)
    truck_type = models.ForeignKey(truck_type, on_delete=models.CASCADE, related_name='dispatch_type')
    truck_name = models.ForeignKey(truck_name, on_delete=models.CASCADE, related_name='dispatch_name')
    origin = models.CharField(max_length=255, default=0)
    destination = models.CharField(max_length=255, default=0)
    total_trucks = models.IntegerField(default=0)
    material_type = models.CharField(max_length=255, default=0, choices=mtypes)
    scheduled_date = models.DateTimeField(max_length=255, default=0)
    offered_price = models.IntegerField(default=0)
    weight = models.IntegerField(default=0)
    status = models.CharField(max_length=255, default='Active', choices=bid_status_choices)
    created_on = models.DateTimeField(auto_now_add=True)
    route_distance = models.IntegerField(default=0)
    route_tat = models.CharField(max_length=255, default=0)
    etd = models.DateTimeField(default=timezone.now)
    eta = models.DateTimeField(default=timezone.now)
    route_link = models.CharField(max_length=255, default=0)

Answer 1

模型实例不是字典，它们是具有属性的对象。您需要使用点符号：

'data': list(map(lambda row: {'name': row.weight, 'y': row.route_distance}, dataset))

还请注意，此代码不是特别的Pythonic代码。使用列表理解更为习惯：

'data': [{'name': row.weight, 'y': row.route_distance} for row in dataset]

TypeError：“ abc”对象不可下标

1 个答案: