Python nested dictionary traversal

Question

I am new to python and I am having some trouble with finding a nice way to complete my task

given i have a dictionary similar to this

x = {
"rackList": [
    {
        "rackType": "apc",
        "serverList": [
            {
                "serverType": "x4950",
                "serverIp": "192.168.0.1",
            }
        ],
        "position": 1
    },
    {
        "rackType": "apc",
        "serverList": [
            {
                "serverType": "x4950",
                "serverIp": "192.168.0.2",
            }
        ],
        "position": 2
    },
    {
        "rackType": "apc",
        "serverList": [
            {
                "serverType": "x4950",
                "serverIp": "192.168.0.3",
            }
        ],
        "position": 3
    },
    {
        "rackType": "apc",
        "serverList": [
            {
                "serverType": "x4950",
                "serverIp": "192.168.0.4",
            }
        ],
        "position": 4
    }
]}

I need to extract the server IP from each serverList, so currently I am doing this:

y = []

for i in x['rackList']:
    for j in i['serverList']:
        y.append(j['serverIp'])

I would like to know if there is a more python like or more elagent way of achieving the same result.

Thanks in advance

Answer 1

Yes, it's called a list comprehension :

y = [server['serverIp'] for rack in x['rackList'] for server in rack['serverList']]
# ['192.168.0.1', '192.168.0.2', '192.168.0.3', '192.168.0.4']