how to use variables to read in nested json-CodePudding

I want to read in a nested json like

"Experiment"{
        "rats"{
            "animal":[1,2,3,4]
              }
        "dogs"{
            "animal":[1,2,3,4]
              }
            }

(I hope I set all the brackets correctly)

Now I want to make it variable to read in Dogs or rats (do not worry, I am not actually experimenting on animals :-) )

So instead of

conf=pd.read_json(filepath)
animal=conf[Experiment][dogs][1]

I would like to use

conf=pd.read_json(filepath)
a="dogs"
b="rats"
animal=conf[Experiment]a[1]

Can someone hint how to do this? Thanks

CodePudding user response：

You essentially have the answer within your question, as long as you clean up the syntax. If you change your json to this:

{
    "Experiment": {
        "dogs": {
            "animal": [ 1, 2, 3, 4 ]
        },
        "rats": {
            "animal": [ 1, 2, 3, 4 ]
        }
    }
}

(Note the comma after "dogs", surrouding {} and : to separate keys and values) You can do it the first way with:

import pandas as pd

conf = pd.read_json("animals.json")
animal = conf["Experiment"]["dogs"]["animal"]

Or the way you wanted with:

import pandas as pd

a = "dogs"
conf = pd.read_json("animals.json")
animal = conf["Experiment"][a]["animal"]

I assumed what you're trying to grab is the array [1,2,3,4], but if you want "animal": [1,2,3,4], just leave off ["animal"] from above. Your question lacks quotes around the keys, so that was likely your issue. You can easily set a variable to be the string of the key you're looking for ("dog") and use that. You also attempted to index dogs with [1], but dogs isn't an array, so perhaps you meant to put [] around "animal": [ 1, 2, 3, 4 ] instead of {}?

Also, you don't necessarily need to use pandas (unless you're doing a lot more other than mentioned here). You can also do it like so:

import json

a = "dogs"
f = open("animals.json")
conf = json.load(f)
animal = conf["Experiment"][a]["animal"]