Json NoneType 对象的 Python 类型错误

我正在从一个多嵌套的json文件中读取.我已经创建了一个用于从json获取特定密钥的类，然后将其创建到一个数据帧中.

现在，如果密钥存在，则一切都按预期工作，并且找不到密钥时，我会得到以下错误

TypeError:‘NoneType’对象不可订阅

下面是一个样例json和代码快照

output = {"records":[{
    "ID":{
        "$":"123456"
    },
    "Records":{
        "ChildRecord":{
            "Address":[
                {
                    "$": "24 Street"
                }
            ]
        }
    }
},{
    "ID":{
        "$":"456789"
    },
    "Records":{
        "ChildRecord":{
            "Address":[
                {
                    "$": "57 New Town"
                }
            ]
        }
    }
}]}

identifier = [o.get('ID').get('$') for o in output['records']] 
address = [o.get('Records').get('ChildRecord').get('Address')[0].get('$') for o in output['records']]
print(identifier,'identifier')
print(address,'address')

由于密钥存在，因此我得到以下输出

identifier ['123456','456789'] 
address ['24 Street','57 New Town']

If the "Address" key is not present in one of the record then I get the type error, TypeError:‘NoneType’对象不可订阅. How to overcome this issue and get the output as

identifier ['123456','456789'] 
address ['24 Street',None]

此外，在某些情况下，我会在多个密钥中获取地址

"Address":[
                    {
                        "$": "57 New Town"
                    },
                    {   
                        "$": "New Castle Road"
                    },
                    {   
                        "$": "PO Box 309"
                    }
                ]

有没有办法将整个地址读作

['24 Street','57 New Town, New Castle Road, PO Box 309']