可以使用递归来遍历嵌套JSON对象。以下是一个示例代码：

def loop_through_nested_json(json_obj):
    if isinstance(json_obj, dict):
        for key in json_obj:
            value = json_obj[key]
            if isinstance(value, (dict, list)):
                loop_through_nested_json(value)
            else:
                print(key, ":", value)
    elif isinstance(json_obj, list):
        for item in json_obj:
            loop_through_nested_json(item)

使用上述函数，可以遍历任何嵌套JSON对象并打印出其键和值。例如：

json_obj = {
    "name": "John",
    "age": 30,
    "hobbies": ["reading", "music"],
    "address": {
        "street": "123 Main St",
        "city": "New York",
        "state": "NY"
    }
}
loop_through_nested_json(json_obj)

将输出以下内容：

name : John
age : 30
hobbies : reading
hobbies : music
street : 123 Main St
city : New York
state : NY