How to read data from a list in a json object-CodePudding

I have JSON data that I need to read and then print:

json_load =\
{"city": {"coord": {"lat": 52.2183, "lon": 6.8958},
          "country": "NL",
          "id": 2756071,
          "name": "Enschede",
          "population": 153655,
          "sunrise": 1656472443,
          "sunset": 1656532643,
          "timezone": 7200},
 "cnt": 40,
 "cod": "200",
 "list": [{"clouds": {"all": 50},
           "dt": 1656536400,
           "dt_txt": "2022-06-29 21:00:00",
           "main": {"feels_like": 295.23,
                    "grnd_level": 1007,
                    "humidity": 60,
                    "pressure": 1012,
                    "sea_level": 1012,
                    "temp": 295.38,
                    "temp_kf": 2.77,
                    "temp_max": 295.38,
                    "temp_min": 292.61},
           "pop": 0,
           "sys": {"pod": "n"},
           "visibility": 10000,
           "weather": [{"description": "scattered clouds",
                        "icon": "03n",
                        "id": 802,
                        "main": "Clouds"}],
           "wind": {"deg": 99, "gust": 1.93, "speed": 1.9}}]}

Now I want to read: feels_like, temp, etc. I can read the first part on top with:

print(json_load['city']['coord'])

But if I want to read:

print(json_load['list']['main'])

I get a keyword error 0.

CodePudding user response：

Since json_load['list'] is a list, you have to use indices to access the items in it. Here's how to get the contents of the first (zeroth) element of it:

print(json_load['list'][0]['main']['feels_like'])  # -> 295.23
print(json_load['list'][0]['main']['temp'])  # -> 295.38

CodePudding user response：

I would personally use something like dotwiz for fast, easy attribute-style access with dict and nested dict objects. This library is available on pip:

pip install dotwiz

Usage:

from dotwiz import DotWiz

json_load = {
    "city": {
        "coord": {
            "lat": 52.2183,
            "lon": 6.8958
        },
    },
    "list": [
        {
            "main": {
                "feels_like": 295.23,
                "temp": 295.38,
            },
        }
    ]}


dw = DotWiz(json_load)

print(dw)
print(dw.city.coord)
print()

assert dw.city.coord.lon == 6.8958

print('temp:', dw.list[0].main.temp)
print('feels like:', dw.list[0].main.feels_like)

Prints:

✫(city=✫(coord=✫(lat=52.2183, lon=6.8958)), list=[✫(main=✫(feels_like=295.23, temp=295.38))])
✫(lat=52.2183, lon=6.8958)

temp: 295.38
feels like: 295.23

If you need field auto completion and type hinting support for use in an IDE, I would suggest to subclass from DotWiz, and then define only the fields you want to access:

from __future__ import annotations

from dotwiz import DotWiz


class MyDotClass(DotWiz):
    city: City
    list: list[ListData]

class City:
    coord: Coord

class Coord:
    lat: float
    lon: float

class ListData:
    main: Main

class Main:
    feels_like: float
    temp: float


dw = MyDotClass(json_load)
# rest same as above...

Disclaimer: I am the creator and maintener of this library.