无法访问其中包含列表的嵌套 Python 字典

Question

我有下面的嵌套字典：

facter_networking: {"domain": "mylab.com", "fqdn": "mylab.com", "hostname": "mylab", "interfaces": {"ens192": {"bindings": [{"address": "20.9.8.1", "netmask": "255.255.255.221", "network": "20.33.50.62"}], "ip": "20.67.83.48", "mac": "00:00:06:0:e0:d6", "mtu": 1500, "netmask": "255.255.255.224", "network": "20.67.83.48"}, "ens224": {"bindings": [{"address": "20.67.83.48", "netmask": "20.67.83.48", "network": "20.67.83.48"}], "ip": "20.67.83.48", "mac": "20.67.83.48", "mtu": 1500, "netmask": "255.255.255.224", "network": "20.67.83.48"}, "lo": {"bindings": [{"address": "127.0.0.1", "netmask": "255.0.0.0", "network": "127.0.0.0"}], "ip": "127.0.0.1", "mtu": 65536, "netmask": "255.0.0.0", "network": "127.0.0.0"}}, "ip": "20.67.83.48", "mac": "00:00:00:9d:8f:d7", "mtu": 1500, "netmask": "255.255.255.224", "network": "20.67.83.48", "primary": "ens224"}

我可以读取大部分 Keys 值，但其中一些我不能。

例如：

print(myfile['facter_networking']['domain']) - it works.
print(myfile['facter_networking']['fqdn']) - it works.
print(myfile['facter_networking']['hostname'])    - it works.

如果我这样做了。

print(myfile['facter_networking']['interfaces']['ens192']['bindings']['address']) - It doens't work.

另一方面，如果我这样做：

print(myfile['facter_networking']['interfaces']

我得到结果：

{"ens192": {"bindings": [{"address": "20.9.8.1", "netmask": "255.255.255.221", "network": "20.33.50.62"}], "ip": "20.67.83.48", "mac": "00:00:06:0:e0:d6", "mtu": 1500, "netmask": "255.255.255.224", "network": "20.67.83.48"}, "ens224": {"bindings": [{"address": "20.67.83.48", "netmask": "20.67.83.48", "network": "20.67.83.48"}], "ip": "20.67.83.48", "mac": "20.67.83.48", "mtu": 1500, "netmask": "255.255.255.224", "network": "20.67.83.48"}, "lo": {"bindings": [{"address": "127.0.0.1", "netmask": "255.0.0.0", "network": "127.0.0.0"}], "ip": "127.0.0.1", "mtu": 65536, "netmask": "255.0.0.0", "network": "127.0.0.0"}}, "ip": "20.67.83.48", "mac": "00:00:00:9d:8f:d7", "mtu": 1500, "netmask": "255.255.255.224", "network": "20.67.83.48", "primary": "ens224"}

知道如何访问上面的这些值吗？

Answer 1

正如评论部分所说，{"bindings": [{"address" 是一个列表。与往常一样，如果您尝试使用索引访问空列表，它将引发异常。而是循环遍历它，以便在列表为空的情况下得到空列表

In [66]: [i["address"] for i in myfile['facter_networking']['interfaces']['ens192']['bindings']]
Out[66]: ['20.9.8.1']

Answer 2

快速修复： 您的问题在于您对最后一个嵌套字典“地址”的访问。由于它在成为字典之前嵌套在列表中，因此您应该这样获取它：

myfile['facter_networking']['interfaces']['ens192']['bindings'][insert desired index here]['address']

更好的修复： 但是，您目前有一个巨大的设计问题。在 dicts in dicts in dicts in list 中嵌套 dicts 是一个嵌套地狱，它通过使调试发生的任何事情变得更加困难，从而阻止您有效地编码。幸运的是，python 是一种面向对象的语言！您可以将大部分字典替换为专用对象，从而更好地有效管理您的代码，并降低未来发生此类错误的可能性。

Answer 3

问题是您尝试访问像字典这样的列表：

...{"bindings": [{"address": "20.9.8.1...

访问您需要的地址

....["bindings"][0]["address"]

Answer 4

d = {
    'facter_networking': {
        "domain": "mylab.com",
        "fqdn": "mylab.com",
        "hostname": "mylab", 
        "interfaces": {
                        "ens192": 
                                {
                                "bindings": [{"address": "20.9.8.1", "netmask": "255.255.255.221", "network": "20.33.50.62"}],
                                "ip": "20.67.83.48", "mac": "00:00:06:0:e0:d6", "mtu": 1500, "netmask": "255.255.255.224", "network": "20.67.83.48"}, 
                                "ens224": {"bindings": [{"address": "20.67.83.48", "netmask": "20.67.83.48", "network": "20.67.83.48"}], 
                                "ip": "20.67.83.48", "mac": "20.67.83.48", "mtu": 1500, "netmask": "255.255.255.224", "network": "20.67.83.48"}, 
                                "lo": {"bindings": [{"address": "127.0.0.1", "netmask": "255.0.0.0", "network": "127.0.0.0"}],
                                "ip": "127.0.0.1", "mtu": 65536, "netmask": "255.0.0.0", "network": "127.0.0.0"}},
        "ip": "20.67.83.48", "mac": "00:00:00:9d:8f:d7",
        "mtu": 1500, "netmask": "255.255.255.224", "network": "20.67.83.48", "primary": "ens224"
    }
}

print(d['facter_networking']['interfaces']['ens192']['bindings'][0]['address'])

输出：

20.9.8.1