get AttributeError解析JSON数据

Question

我从服务器得到一个JSON数据，我需要单独解析它，当我用SimpleNamespace这样做时，我得到了问题。如何解析这些数据?

示例数据:

{
"version":"1.0",
"packageName":"com.some.thing",
"eventTimeMillis":"1503349566168",
"subscriptionNotification":
{
"version":"1.0",
"notificationType":4,
"purchaseToken":"PURCHASE_TOKEN",
"subscriptionId":"my.sku"
}
}

我代码:

import json
from types import SimpleNamespace
def callback(message):
x = json.loads(message.data, object_hook=lambda d: SimpleNamespace(**d))

print("Version: " + x.version)
print("Package Name: " + x.packageName)
print("Time Milis: " + x.eventTimeMillis)
print("Token: " + x.subscriptionNotification.purchaseToken)
print("Product: " + x.subscriptionNotification.subscriptionId)
print("Type: " + str(x.subscriptionNotification.notificationType))

错误:

AttributeError: 'types.SimpleNamespace' object has no attribute 'subscriptionNotification'

Answer 1

在这个例子中，我们从一个字典开始。从那时起，代码就很少了，整个事情就变成了"表驱动"。例如，如果您的字典结构发生了变化，需要向顶层添加一个新键，那么只需对L1表进行相应的更改。希望这能给你一些如何继续下去的想法:

D = {
"version": "1.0",
"packageName": "com.some.thing",
"eventTimeMillis": "1503349566168",
"subscriptionNotification":
{
"version": "1.0",
"notificationType": 4,
"purchaseToken": "PURCHASE_TOKEN",
"subscriptionId": "my.sku"
}
}

def doPrint(d, L):
if d:
for _l in L:
print(f'{_l[0]}: {d.get(_l[1], "n/a")}')

L1 = [['Version', 'version'],
['Package Name', 'packageName'],
['Time Millis', 'eventTimeMillis']
]
L2 = [['Token', 'purchaseToken'],
['Product', 'subscriptionId'],
['Type', 'notificationType']
]
doPrint(D, L1)
doPrint(D.get('subscriptionNotification', None), L2)