我如何访问python中的嵌套字典

Question

请帮我查看嵌套词典：

moo = {'dell': {'strength': {}, 'weakness': {}},'ibm': {'strength': {}, 'weakness': {}}}

我可以使用以下方式访问父键：

for k in moo.keys():
    print k

如何访问子键？

Answer 1

只需遍历每个项目：

for k in moo.keys():
    print k # 1st level key
    for sk in moo[k].keys():
        print sk # 2nd level subkey

这应该打印

ibm
weakness
strength
dell
weakness
strength

Answer 2

使用dict.items()方法！

for maker, properties in moo.items():
    for property, values in properties.items():
        print(maker, property, values)

输出：

dell strength {}
dell weakness {}
ibm strength {}
ibm weakness {}

要访问单个元素，只需链接[key] - 调用：

moo['dell']['strength']

输出：

{}

Answer 3

使用嵌套for循环：

for k in moo:
    for i in k.keys():
        print i

或直接访问它们：

moo['dell']['strength']